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Monitoring of Positive List System on Residual Pesticides Analysis of Agricultural Products in Southwest of Korea
Abstract
Pesticide residues must be managed for food safety and regulations are being strengthened worldwide. In Korea, the Positive List System (PLS) was introduced to prevent the misuse and manage unregistered pesticides. The PLS is a system that applies 0.01 mg/kg to crops for which maximum residue limits is not set. A more stringent regulatory system could lead to an increase in agricultural products that exceed standards. Therefore it is necessary to confirm the change in the determination rate of agricultural products exceeding the previous pesticide residue standards. In terms of climate change, temperature increase and changes in precipitation patterns are the main pest and pathogen infection determinants. Complex interactions and climate variability will lead to more frequent spraying of pesticides and eventually affect consumer exposure at the end of the food chain. Therefore, we confirmed the relationship between temperature and precipitation, which are climate factors and pesticide residues. Agricultural products (n=5,560) distributed at wholesale market (SeoBu, GakHwa) in the southwest Korea were collected and 311 kind of residual pesticides were analyzed using GC-MS/MS and LC-MS/MS. This study could serve as basic data for pesticide residue prevention, management, control and monitoring in countries seeking to tighten pesticide standards.
Keywords: Pesticideresidues/analysis/management; Agricultural products/vegetables; Positive List System; Maximum Residue Limit; Climate change; Consumer product safety
Abbreviations: PLS: Positive list system; MRLs: Maximum residue limits; GC: Gas chromatography; LC: Liquid chromatography; MS: Mass spectrometry; GC-MS/MS: Gas chromatography tandem mass spectrometry; LC-MS/MS: Liquid chromatography tandem mass spectrometry; LOD: Limit of detection; LOQ: Limit of quantitation; RSD: Relative standard deviation
Introduction
Pesticides are historically long-established commodities used in agriculture [1]. They include a wide range of compounds such as insecticides, fungicides, herbicides, and rodenticides [2]. Pesticides play an important role in reducing damage from weeds, diseases, and pests, and improving crop yield worldwide [2], but adversely impact the environment. The pesticides not only contaminate soil, surface water, and groundwater, but also remain in trace amounts in crops, threatening human health [2]. In humans, pesticides can be carcinogenic and cytotoxic and can cause bone marrow and nerve disorders, infertility, and immune and respiratory diseases [3]. The presence of large amounts of pesticide residues in food is a serious risk to consumers. In general, pesticides are applied directly to crops and they can remain on them. Infants, children, and adults can be exposed to these pesticides by consuming pesticide-contaminated food [4]. Residues of chemical pesticides have been detected more in vegetables and fruits than in other food items4. As agricultural product intake is a major pathway by which humans are exposed to pesticides, there is an increasing demand for safe food management from pesticide residues worldwide.
The European Commission, Environmental Protection Agency, Food and Agriculture Organization/World Health Organization have set limits on pesticide residues in food to protect people from the toxic effects of pesticide exposure [4]. Acceptable levels of pesticide residues in food are defined by setting a maximum residue limit (MRL) for each component. An MRL represents the highest concentration of a pesticide residue legally permitted in food when a pesticide is used correctly on an agricultural product. In Korea, the pesticide residue monitoring program was started in 1968 [5] and as a part of strengthening the food safety management, the introduction of a pesticide Positive List System (PLS) was planned in 2011 [6]. The PLS is a system that applies a uniform standard MRL of 0.01 mg/kg of chemical residues to crops that do not have pesticide residue tolerance standards. Priority was given to nuts, seeds, and tropical fruits in December 2016 [6]. Since January 2019, it has been fully expanded to domestic and imported agricultural products6. In other words, the PLS system was introduced to strengthen the pesticides management within the allowable daily intake range by uniformly applying the default MRL of 0.01 mg/kg. This system can ensure food safety for consumers by preventing in advance the use of unregistered pesticides and excessive spraying of pesticides.
However, there are concerns about the introduction of the PLS system in agricultural sites due to the insufficient number of registered pesticides, the problem of unintended pesticide residues, the problem of scattered contamination during pesticide application, residual problem of succeeding crop and soil residues [7]. A more stringent regulatory system, PLS, could lead to an increase in agricultural products that exceed standards. Therefore, after the expansion of the PLS to the assessment of all agricultural products, it is necessary to confirm that the change in the determination rate of agricultural products exceeds the earlier standard for pesticide residues. In some studies, the introduction of the PLS, which was expanded since 2019, did not affect the assessment result (conformity/nonconformity) for agricultural products exceeding the pesticide residue standard [7,8]. However, there may be differences according to the cultivation area of crops, and extensive studies have not been conducted. In terms of improving food safety and agricultural practices and minimizing economic losses, the pesticide residue monitoring program in food is very important, and the expanded application of PLS system has the potential to affect the cultivation and distribution of agricultural products, so comprehensive studies are required.
Several studies have found a correlation between the pesticide use and climate change [9-11]. Pesticide use is directly and indirectly related to climate change11. However, there have only been a few studies on establishing the relationship between pesticide residues and climate change for more than 5,000 agricultural products of various types. Despite tremendous improvements in technology and crop yield potential, food production remains highly dependent on climate, because solar radiation, temperature, and precipitation are the main drivers of crop growth [12]. In terms of climate change, temperature increase and changes in precipitation patterns are the main pest and pathogen infection determinants [12]. Complex interactions and climate variability will lead to more frequent spraying of pesticides and eventually affect consumer exposure at the end of the food chain [11]. As the impact of climate change grows, ensuring food safety while improving agricultural productivity through the use of pesticides is a huge challenge. Accordingly, we attempted to confirm the correlation between pesticide residues and climatic factors. The purpose of this study was to monitor pesticide residues in agricultural products in the southwest region of Korea and to investigate whether the introduction of a PLS system affects decisions of conformity and nonconformity. Furthermore, the relationship with pesticide residues between temperature and precipitation, which are climatic factors, was examined for more than 5,000 agricultural products of various types.
Material and Methods
Sample collection
This study was conducted at the Health and Environment Research Institute (Agro-Fishery Products Inspection Center) in Gwangju metropolitan city under a surveillance program of the Gwangju metropolitan government. A total of 5,560 agricultural products were collected between March 2020 and September 2021 from the largest wholesale market in the southwest of Korea, and all samples were analyzed within 24 h of collection. The types of agricultural products analyzed in this study are listed in Table 1.
Pesticide reference standard and Reagents
The certified pesticide reference standards were purchased from AccuStandard (New Haven, USA) or Kemidas (Suwon-si, Republic of Korea). A total of 311 pesticides that can be analyzed simultaneously were selected for analysis and are listed in Table 2. The reagents and solvents used for monitoring the pesticide residues, viz., acetonitrile, sodium chloride, acetone, and water containing 0.1% (v/v) formic acid, were procured from Merck (Darmstadt, Germany). Anhydrous sodium sulfate, n-hexane, and dichloromethane were purchased from Wako (Osaka, Japan), and methanol was purchased from Avantor (USA).
Sample preparation
The overall analysis was conducted using multi-class pesticide multi-residue method No. 2 for pesticide residues, in accordance with the Korean Food Code guidelines. The samples (1-2 kg of each agricultural product) were first pulverized using a blender (Robotcoupe, South Perkins, Ridgeland, USA) to obtain a homogeneous mixture. Then, 50 g of each sample was extracted with 100 mL of acetonitrile for 3 min. The sample/acetonitrile mixture was homogenized for 3 min and filtered using a Buchner funnel into a bottle containing 10 g of sodium chloride. Thereafter, the extract and sodium chloride were vortexed and the layers were separated. Then, 10 mL of the acetonitrile layer was transferred to a test tube and evaporated to dryness in a water bath using a stream of air at 40 °C or lower. For the purification of the pesticide extract, gas chromatography (GC) and liquid chromatography (LC) were performed independently.
For GC analysis, Florisil cartridges (Phenomenex, Torrance, CA, USA) were activated and conditioned by flowing 5 mL of hexane and 5 mL of 20% acetone/hexane. The sample extract was dissolved in 4 mL of 20% acetone/hexane and loaded into the Florisil cartridge, and the cartridge was eluted with 5 mL of 20% acetone/hexane. The eluate was collected in a tube and the solvent was evaporated under gentle air flow. The residue was then dissolved in 2 mL of acetone, filtered through a membrane filter (PTFE, 0.45 μm), and used as the test solution for GC analysis. For LC analysis, aminopropyl cartridges (Phenomenex, Torrance, CA, USA) were first activated and conditioned with 5 mL of dichloromethane. Then, the extracted solution was loaded and eluted with 4 mL of 1% methanol/dichloromethane, and the eluate was collected in a tube. The cartridge was eluted again with 7 mL of 1% methanol/dichloromethane. The combined solution of first elution and second elution was evaporated under gentle air flow at 40 °C in a water bath. The dried extract was dissolved in 2 mL of acetonitrile and filtered through a membrane filter (PTFE, 0.2 μm) for use as a test solution for LC analysis.
Pesticide residue analysis conditions
GC- MS (GC-tandem MS (GC-MS/MS), Agilent 7000B, California, USA) and LC-MS (LC- tandem MS (LC-MS/MS), AB SCIEX, TQ 4500, CA, USA) were used for the qualitative analysis of the pesticide residues. The quantitative analysis of each pesticide was carried out using a GC-MS/MS system, LC-MS/MS system, GC system equipped with a 63Ni electron capture detector (ECD), and GC system equipped with a nitrogen phosphorous detector (NPD), according to the Food Code set by the Korea Food and Drug Administration. An Agilent 7890 series GC instrument equipped with an NPD and ECD was used for GC analysis. LC analysis, electrospray ionization was performed in positive and negative modes, and the data were obtained in multiple reaction monitoring mode. The qualitative and quantitative instrument analysis conditions are presented in Table 3 & 4.
Measurement of recovery, LOD and LOQ
Method validation was performed based on SANCO/12571/2013 [13] and ICH/2005/Q2/R1 [14]. To a blank matrix sample of lettuce in which no residual pesticide was detected, each pesticide standard was added so that the sample content was 0.5 mg/kg, and the recovery was measured by repeating it three times. The limit of detection (LOD) and limit of quantitation (LOQ) were calculated as the standard deviation of the slope and residual through the regression line presented by the International Conference on Harmonization. It was repeated five times for each concentration using a standard solution and measured according to the following formula.
σ = standard deviation of the response
S = slope of calibration curve
Investigation of the impact of nonconformity due to the introduction of PLS
The detection and nonconformity assessment of each pesticide/item in the pesticide residues of agricultural products were conducted using Excel 2016 (Microsoft, Redmond, WA, USA). In order to determine the change in the nonconformity of the pesticide residues under the PLS, the data of nonconforming agricultural products were evaluated for suitability by applying the pesticide residue standards used before the introduction of the PLS. This method was applied according to the method specified in the Korean Food Code. The standard application sequence is as follows:
a. Application of Codex standards to agricultural products.
b. Application of the standards in the order of agricultural products, sub-categories, and major categories of the pesticide residue standards of the Food Code.
c. Application of the lowest standard among the pesticide standards for the pesticide compound in the Food Code.
Statistical Analyses
All statistical analyses were performed in SPSS version 22.0 software (IBM Corp., Armonk, NY, USA) and P-values less than 0.05 were considered statistically significant. Log transformation of data was performed where appropriate. Data analysis was calculated as mean ± standard deviation and all tests were twosided. Normal distribution of the variables was confirmed with a Kolmogorov–Smirnov (KS) test. And then we calculated the Pearson linear correlation coefficient in order to seek to determine the strength of association between data sets. The following points are the accepted guidelines for interpreting the correlation coefficient, and the results were interpreted based on this : perfect (|r| = 1), strong (0.7 ≤ |r| < 1.0), moderate (0.3 ≤ |r| < 0.7), weak (0.0 < |r| < 0.3), No correlation (|r| = 0) [15].
Results and Discussion
Validity of analytical methods
For the validation of the method, forty kinds of pesticides were selected based on the detection of more than twenty times in agricultural products. The method was validated for various parameters such as accuracy, precision, linearity, limit of detection and quantification (Table 5). The adequacy of the sample pretreatment was evaluated based on the recovery, and the analytical method was validated based on ICH guidelines [14]. The recovery was between 79.13 and 115.05% and the relative standard deviation (%RSD) values were less than 6%. A linear correlation between each pesticide concentrations and peak areas was obtained in the range of 0.9971 to 1.000. The limit of detection (LOD) were 0.001 to 0.019 mg/kg for GC-MS/MS and 0.001 to 0.004 mg/kg for LC-MS/MS. The limit of quantification (LOQ) were 0.004 to 0.058 mg/kg for GC-MS/MS and 0.002 to 0.013 mg/kg for LC-MS/MS. The validated parameters were found to be within acceptable ranges, suggesting that this method is suitable for use in the pesticide analysis of agricultural products.
Climate factors and pesticide residues of agricultural products
In this study, 5,560 agricultural products were monitored. Pesticide residues were detected in 51.1% of the agricultural products and the pesticide residues in 2.0% of the agricultural products were found to exceed the MRLs. The detection and nonconformity rates were categorized according to the four seasons in Korea, and the detection and nonconformity rates for 2020 and 2021 are shown in Figure 1. On average, the detection rate (nonconformity rate) was as follows: spring 46.4% (1.9%), summer 52.7% (1.6%), autumn 56.8% (2.1%), and winter 50.0% (3.2%). It was thus confirmed that the detection rate was the highest in autumn, while the nonconformity rate was the highest in winter. Different climates occur according to the season, and they have a major impact on the cultivation of agricultural products. Therefore, the relationship between climatic factors and pesticide residues in agricultural products was assessed. The climatic factors (temperature and precipitation) were obtained from the statistical data of the Korea Meteorological Administration [16]. It was analyzed using the average values of climate factors in Gwangju, Jeollabuk-do and Jeollanam-do, which are representative regions of the southwest region and account for most of the wholesale market products. The normality of experimental results is an important premise for the use of parametric statistical tests such as correlation analysis. If the assumption of normality is not confirmed by relevant tests, interpretation and inference from any statistical test may not be reliable or valid [17].
Normal distributions of all variables such as temperature, precipitation, detection rate, and nonconformity rate were confirmed by the Kolmogorov-Smirnov (KS) test, and all variables satisfied the normality with a significance probability p=0.200 Figure 2a & b. shows the relationship between the temperature and pesticide residues. Pearson correlation coefficient (r) between temperature and detection rate was 0.314 (p = 0.190). There was no significant change in the detection rate of the pesticide residues according to the temperature change. However, the nonconformity rate showed an opposite trend with respect to the temperature. Pearson correlation coefficient (r) between temperature and nonconformity rate was -0.765 (p = 0.000). It can be seen that there is a high negative correlation between temperature and nonconformity rate as high as 76.5%. Most winter agricultural products are grown in facility and the density of phytopathogenic fungi increases rapidly due to low temperature and high humidity, insufficient sunlight and poor ventilation. Therefore, it is judged that the frequent use of pesticides increased the nonconformity rate [18]. Moreover, several studies have shown that pesticide residue levels were higher in greenhouse-grown produce than in open field-grown produce Figure 2c & d [19,20]. shows the relationship between the precipitation and pesticide residues. Pearson correlation coefficient (r) between precipitation and detection rate was 0.200 (p = 0.411). Precipitation did not have a significant effect on the detection rate. On the other hand, As the correlation coefficient R= -0.701 (p = 0.001), it can be seen that there is a high negative correlation between precipitation and nonconformity rate as high as 70.1%. When there was a large amount of precipitation in July and August of 2020, the nonconformity rate decreased at first and then increased. Ilse Delcour confirmed that high precipitation causes pesticide dissipation, leading to a general tendency of increased pesticide use to overcome the loss [11]. According to our study results, the increase in the detection of pesticide residues after a large amount of precipitation can be considered as the corresponding effect. Considering the results of the study, it suggests that caution is needed in managing pesticides and consuming agricultural products during autumn (high detection rate), winter (high nonconformity rate), and after periods of consecutive precipitation (high nonconformity rate). In a previous study conducted in the USA, the usage of pesticides in the cultivation of each agricultural product was investigated according to the climate change to discover that the usage pattern of pesticides for each agricultural product differed according to the climate [9]. This suggests that the relationship between climate and pesticide residues may be different for each agricultural product. Therefore, in order to accurately identify the relationship between climate and pesticide residues, additional climate-related studies according to cultivated agricultural products and cultivation methods are needed. Our study was conducted for a short duration, and a longer study duration is necessary to adequately assess the relationship between temperature, precipitation, and residual pesticide detection. But, our research can be considered representative because more than 5,000 agricultural products were monitored.
Monitoring of pesticide residues in agricultural products
The detection rates of residual pesticides in the agricultural products (51.1% of the total number of products studied) are as follows: chili pepper (74.1%), crown daisy (73.0%), chwinamul (67.9%), perilla leaves (67.6%), and chives (66.7%). On the other hand, none of 102 cases of king oyster mushroom were detected (Table 6). A high detection rate of pesticide residues has been observed for chili pepper cultivated in several regions, including Saudi Arabia [21], Cameroon [22], and Southeast Asia [23]. Of the 311 pesticides monitored, 126 pesticides were detected, and 20 types of frequently detected pesticides are shown in Figure 3. The most frequent pesticides were fluopyram (n = 408), chlorfenapyr (n = 383), chlorantraniliprole (n = 320), fludioxonil (n = 287), and thiamethoxam (n = 287). Five pesticides detected with high frequency corresponded to three compounds in an insecticide and two compounds in a fungicide. In the case of fluopyram, lettuce (n = 81), chives (n = 70), crown daisy (n = 45), and cucumber (n = 33) had the highest frequencies. Chlorfenapyr was detected in chives (n = 66) and chili pepper (n = 51), while chlorantraniliprole was detected in young radish (n = 55) and winter cabbage (n = 43). Fludioxonil was detected at a high frequency in chives (n = 61), pimpinella brachycarpa (n = 41), while thiamethoxam was detected in young radish (n = 49) and crown daisy (n = 43). The MRLs of fluopyram have been set for 74 commodity standards in the Korean Food Code. In Korea, among agricultural products with a high non-conformity rate, a temporary residual limit of fluopyram is enforced for chives and crown daisy. If these standards are eliminated, and agricultural products are regulated according to the PLS, the nonconformity rates may increase. This also applies to other pesticide residues; that is, the introduction of PLS can lead to a stricter management of pesticide residues.
Monitoring of the nonconforming agricultural products
In our study, a total of 112 agricultural products of 31 types were found to exceed the 118 residual pesticide standard, including duplicate detection (Table 7). There were many nonconforming agricultural products in the order of crown daisy (n = 20), chives (n = 10), chwinamul (n = 9), pimpinella brachycarpa (n = 8), and lettuce (n = 6). A comparison of nonconformity rate of each agricultural product revealed that agricultural products exceeding the MRLs were the most frequent in the order of Sonchus-leaf crepidiastrum (12.5%), Korean cabbage (10.6%), crown daisy (8.7%), Silver divaricata (8.3%), and butterbur leaf (7.7%) Figure 4. shows 32 pesticide components that were deemed to be unsuitable in agricultural products. Some agricultural products contained two pesticides at concentrations exceeding the pesticide residue standards. Fluopyram (n = 17), diazinon, procymidone (n = 11), flubendiamide (n = 10), and chlorothalonil, diniconazole (n = 7) are representative pesticides that exceeded the pesticide residue standards. The fluopyram compound with the highest inconsistency was found in crown daisy (n = 7), chives (n = 5), pimpinella brachycarpa (n = 2), and germinated buckwheat/silver divaricata/spinach in one case each. Agricultural products with a high Nonconformity rate largely included many leafy vegetables/ stalks and stem vegetables. This is related to the permeability of the pesticide and the leaching of the pesticide from the surface of leafy products owing to its solubility in water [24].
Investigation of the impact of the introduction of the PLS on the evaluation of nonconforming agricultural products
Among the agricultural products determined to contain pesticides at levels exceeding the pesticide residue standard, there were 37 agricultural products to which the PLS standard (0.01 mg/kg) was applied, and a total of 20 pesticides were identified 39 times. Diazinon (n = 8) and chlorothalonil (n = 4) are repive pesticides that were determined to be unsuitable at the 0.01 mg/kg standard. According to Method 2.6, the effects of the introduction of the PLS and nonconformity assessment were investigated. A total of 18 agricultural products would not have been deemed as nonconforming if the PLS was not introduced (Table 8). When the standards before the introduction of the PLS system were applied, It was found that the agricultural products belonged to the suitable category in the order of lettuce (n = 3), chwinamul, cucumber and sweet potato stalk (n = 2). In the case of lettuce, which occupied the most number of times, it was found to be suitable when the standard for leaf vegetables, a similar agricultural product, was applied. Therefore, it can be seen that is being managed more strictly with the introduction of PLS, suggesting that lettuce producer education is necessary. Chwinamul, sweet potato stalk and shepherd’s purse are representative minor crops. For minor crops cultivated over a small area, the registration of available pesticides does not meet the demand [25]. There are many types of minor crops and various pests, and accordingly, the registration of pesticides for small-area crops has not been activated, which is a global issue [26]. This causes difficulties in the production of crops and leads to a trend of high pesticide detection rates and nonconformity rates. The expansion of the PLS application implies that as the risk assessment standard of each agricultural product becomes stricter, the concerned agricultural product can be deemed as a nonconforming product. This suggests that the development of harmless pesticides by related organizations is of urgency, and that it is necessary to develop new pesticides to prevent damage to farmers and consumers. In addition, to improve the conformity based on the PLS standards, it is necessary to educate farmers on contamination owing to unintentional mixing of pesticides and appropriate use of suitable pesticides. The results of this study can be used as fundamental data for pesticide management, system supplementation of agricultural products, and reinforcement of field management.
Conclusion
In this study it was confirmed that temperature and precipitation, which are climatic factors, affect the concentration of pesticide residues. According to correlation analysis results, a high detection rate in autumn, high nonconformity rate in low temperature and low precipitation were confirmed. Therefore, we propose the necessity of pesticide management and caution on agricultural products consumption in consideration of climatic factors (autumn, winter, after heavy rain). Pesticide residues were detected in 51.1% and exceeded the MRL in 2.0% of agricultural products. As a result of monitoring the residual pesticide list of agricultural products, the most frequent pesticides were fluopyram, chlorfenapyr and chlorantraniliprole. The most frequent unsuitable agricultural products were daisy, chives, chwinamul, pimpinella brachycarpa and lettuce.
As a result of investigating the effect of the introduction of the PLS standard on the evaluation of non-conforming agricultural products, 18 agricultural products were found to be in the suitable when the previous criteria were applied. Despite the short research period, it was found that food safety could be secured as the standards were strengthened. Therefore farmers should use only registered crops and spray targets for each pesticide, and must comply with the timing and frequency of use. In addition, it is proposed to conduct education of PLS system for various stakeholders such as local government officials, farmers, and pesticide dealers. This study could serve as basic data for pesticide residue prevention, management, control and monitoring in countries seeking to tighten pesticide standards.
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Winter Collection of the Underutilized Berry Corema Album (l.): New Insights on its Maturation Progression
Abstract
Increasing interest in Corema album L. is raising due to the appealing white colour and potential health benefits related to its bioactive composition. White fruits production culminates in late August on coastal dunes, but fruits of various colours are present almost till flowering (late February). We undertook a preliminary physical-chemical characterisation (biometric, CIELab colour, pH, soluble solids content and titrable acidity) of a late fruit collection to disentangle maturity progression and to reveal latent qualities for future utilisation. Irrespective of fruit perceived colouration (white, translucent, brown, brown with black spots and black), the characterized high acidity (1-3 g.100 mL-1) is suggestive that over-mature fruits can still be further explored as food additives. Moreover, using a multivariate exploratory technique, we found a clear fruit’s maturation progression from white/translucent to black, a so-far unreported maturity stage. Addressing gaps in plant phenology and fruit’s maturity behaviour is needed before undertaking cultivation.
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Smallholder Farmers Perceptions and Adaptation Strategies to Climate Change in Ethiopia Review
Abstract
The objective of this review on Smallholder farmers perceptions and adaptation strategies in case Ethiopia. Smallholder households obtain livelihoods through the rural labour market, self-employment in rural non-farm economy, migration and rain-fed agriculture. Agriculture is the major source of rural livelihoods. Climate refers to the average weather and represents the state of the climate system over a given time period. Due to natural variability and human interventions, there is increase in the emission of the greenhouse gases reflecting variation of the mean state of weather variables including temperature, precipitation and wind. Greenhouse gases (GHGs) are more important for their ability to trap heat from the sun and create atmosphere that supports the life on Earth. However increasing levels of these gases is the cause of global temperatures, resulting in the most severe ecological crisis that earth has witnessed in the whole of human history. Adaptation is adjustment in ecological, social or economic systems in response to actual or expected climatic stimuli and the effects or impacts. This term refers to change in processes, practices or structures to moderate or offset potential damage or to take advantages of opportunities associated with changes in climate. It involves adjustment to reduce the vulnerability of community’s regions or activities to climate change and variability. Adaptation is important to climate change issue in two ways- one relating to assessment of impacts and vulnerabilities, the other of the development and evaluation of response options. In Ethiopian diverse type of e climate adaptation strategies considered crop variety; improve crop and livestock, soil and water conservation practices and irrigation. The main factor influence to farmers’ adaptation strategy climate changes such as group of age, family number or size, farm profits, farm dimension, distance to the farm, distance to the market, access to credit, livestock holding, farm to farm extension and access to climate information is basic one. The crucial barrier to type of weather transform altered copy on the farmers’ side are luck of knowledge, lack of capital, lack of sufficient land and luck of information. Therefore, future policy should focus on awareness creation on climate change to adaptation through different ways such as mass media and extensions, encouraging informal social net- works, improving the availability of credit and enhancing research on use of new crop varieties are more suited in different agro ecological zones.
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The Impact of COVID -19 Pandemic on Hospitality (Tourism& HotelSector) and Mitigation Mechanism in Ethiopia review
Abstract
The tourism industry is one of the sectors that would be greatly affected by COVID-19 pandemic. Data for the review was generated from desk review of secondary materials, online blogs and interview through social media chat. Findings of the review reveal that the outbreak of pandemic disease led to rapid shutdowns in cities and states across the country, which greatly affected the hospitality industry. This pandemic showed the rapid negative impact on the country tourism and hotel industry. The findings of the review reveal that COVID-19 has increased cancellations of hotels and travel bookings resulted in revenue loss and unemployment situations, resulting loss of substantial revenue to the government and increasing incidence of poverty among others. The review recommends that provision of alternative service and diversification of service and product and compensation to business operators in the sector to return back to normal operations.
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Analysis of Agricultural Investment Efficiency Based on the Ultra-Efficient Dea Method- Juniper Publishers
To cope with the impact of the financial crisis on China's economy, China has implemented a "four trillion" investment policy to enable China to smoothly weather the financial crisis. However, the growth of investment has led to a decline in investment efficiency. Based on the research sample of 23 provinces from 2008 to 2017, this paper studies the efficiency of Agricultural Investment in China and puts forward some suggestions.
Keywords: Ultra-efficient DEA; Agriculture; Investment Erficiency
Literature review
At present, multi-factor model is the mainstream method to analyze the comprehensive efficiency of investment efficiency. The earliest appearance of this method is traced back to Jefferson (1990) [1], who used the packet model (DEA) to analyze the technical efficiency of China's steel industry, the results show that China's steel industry technology efficiency is low, and some improvement methods are proposed. In the process of rapid development of this method, the whole factor productivity (TFP) method began to emerge, the specific research method is divided into two categories, one kind of scholars use Cobb-Douglas production function, CES production function, etc. to calculate the total factor productivity changes by using the potential output method, by estimating the forward production function, and then calculating the distance between the actual input-output combination and the cutting-edge function. Later, Malmquist S proposed the concept of Malmquist index, but the method was widely used after the DEA method became popular. When the research on investment efficiency of the overall economy matures gradually, many scholars in China have started to combine the current situation of our country and carry out the research on investment efficiency for different sub-industries [2], analyzed the investment efficiency of cultural industry in Hubei Province and concluded that the investment efficiency of cultural industry in this region is in a state of fluctuation and higher than the average of other provinces, but still not effective in DEA, studies the investment efficiency of cultural industry in Shandong Province and concludes by DEA method that the overall investment efficiency of cultural industry in Shandong Province is high, but there are fluctuations in scale efficiency in different years [2]. Puts the perspective on the investment efficiency of hydropower industry and thinks that the investment efficiency and electricity efficiency of hydropower industry in China are low, and the potential for improvement is huge.
Efficiency calculation of agricultural investment
Model selection
The DEA model: At present, the academic method of measuring efficiency is divided into the following two categories, one is the parameter method, mainly includes the amendment of the least square, the cutting-edge production function method and so on, the other is the non-argument method, and the packet analysis method (DEA) is the representative of it. Packet analysis (DEA) is a nonparametric method to measure the relative efficiency value of a decision unit (DMU) in the case of multiple inputs and multiple outputs. For other parameter methods, the DEA model has its unique advantages: 1, the method does not need to set a specific function form, which avoids the error caused by artificially setting the efficiency function equation; The deA model uses input and output data to build an efficiency frontier with all decision units (DMUs) by mathematical planning, and the closer the DMU is to this frontier, the more efficient the DMU efficiency value is 1. Assuming the existence of N decision units (DMU), I input indicators, and J output indicators, the specific form of the DEA model is shown in equations 1-1.
It can be found that the traditional DEA model may have multiple efficiency units equal to 1, at this time cannot distinguish between good and bad in all valid units, so this paper chooses the super-efficiency DEA model for efficiency analysis.
Ultra-efficient DEA model: In view of the disadvantages of the traditional DEA model, Banker e al (1988) puts forward the super-efficient DEA model, the principle is to exclude the DMU to be evaluated from the reference set, so that the effective decision-making unit reorders the advantages and disadvantages. The model is specific to see 1-2. In (1-2), The indicator means the same as the normal DEA model. At this point, the calculated efficiency value of the can be greater than 1, in this paper, the use of DEA solver Pro5.0 software for efficiency analysis.
The efficiency calculation of agricultural input and output
Input and output indicator selection: The data are from the China Statistical Yearbook, the China Financial Statistics Yearbook, the statistical yearbook of the provinces, as well as the wind database, CSMAR database. Agricultural investment efficiency reference [4] selected agricultural fixed asset investment, the end of the year commonly used arable land area, rural working population, rural electricity consumption as input indicators detailed indicator information see Table 1.
The results of the calculation: [4], the method of super-efficiency DEA model is not radially improved, so this paper contains the following assumptions: 1, scale compensation variable, because it is difficult to achieve efficiency under fixed-scale compensation due to legal system, market competition and other reasons; The results are shown in (Tables 2,3) (1) On the whole, the overall investment efficiency of China's agriculture is not high, even in the highest eastern region, the efficiency value is still less than 0.9. In terms of agricultural investment efficiency, the eastern region is much higher than the central region and the western region, and the investment efficiency of the central region and the western region industry is not very different. (2) In terms of comprehensive investment efficiency ranking, Zhejiang, Jiangsu and Fujian ranked first in the agricultural investment efficiency ranking, while Henan and Shandong, the traditional agricultural provinces, ranked lower, indicating that some areas of agriculture are larger, but the investment efficiency is not high the agricultural investment efficiency is high in inner Mongolia [5-7].
Conclusion
Based on the macro data of 23 provinces in China from 2008 to 2017, this paper calculates the efficiency of agricultural investment in China and finds that the overall investment efficiency of agriculture in China is not high, and there are obvious regional differences, and there is still a lot of room for improvement in the level of agricultural modernization and large-scale construction. As a basic industry, the state should give more policy support to improve china's agricultural modernization and large-scale construction level. Microcosmicly, to improve the efficiency of agricultural investment needs to give enterprises more freedom, improve the agricultural economic subject "small, scattered, chaotic" status quo, improve the construction of agricultural industry system, promote industrial integration and development, and thus improve the efficiency of agricultural investment.
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Impact of Cover-Crop Residuals on Soil Carbon Sequestration and Respiration- Juniper publishers
TGlobal policies encourage to lower greenhouse gas emissions in order to maintain climate change under the limit of +2°C at the horizon 2100. An important part of these gases are emitted from croplands and farms [1]. To reduce the environmental impact of croplands, diverse techniques and practices have been widely used by farmers, based on conservation agriculture (simplified cultivation techniques, cover-cropping, agroforestry, etc.). The use of these techniques has been adopted freely, according to the good will of farmers. Scientists have broadly studied these crop management practices in order to evaluate their impact on climate change [2–4]. Actual assessment of carbon emissions and storage capacities of croplands under such crop management practices had helped us to discriminate the practices useful for carbon accumulation. No-tillage has an important role to play in agriculture, mainly because of the great impact on soil bulk density and ease of crop germination. However, it is now well known and admitted that no-till have no significant impact alone on soil carbon storage capacities over the entire soil profile [5]. Cover-cropping is also an interesting and promising management practice to consider when accounting for climate resilient agroecosystems, soil carbon sequestration [6] and ecosystem services [7]. This practice can have very contrasted impacts on soil and the agroecosystem depending on sowing and destruction period, species used, for how long and how the residues are managed. Indeed, cover-cropping leads to improved biomass production and undoubtedly, to more crop residues. The impact of crop residues on soil carbon have been widely studied [8–10], but their impact on soil respiration still needs to be clarified. How do cover crop residues respiration change over the crop season? Soil respiration was measured with an infrared portable gas analyzer together with a soil respiration chamber (EGM4 and SRC1, PP Systems, Amesbury, USA). The study site was located in Southwest France (N 43° 24’ 38.057’’, E 0° 17’ 17.612’’, alt= 266 m) on a soil defined as a Stagnic Luvisol according to the World Reference Base for Soil Resource [11]. No-till and cover-cropping have been implemented for 20 years, which improved soil organic carbon content of 48.8% compared to conventional agricultural system. The cover crop was mainly composed of faba bean (Vicia faba), oat (Avena sativa) and triticale (×Triticosecale) for the last 4 years. We measured soil respiration with and without residues and for residues alone. We observed an increase of soil residues respiration over the season as well as of values dispersion (Figure 1). Very low level of respiration rate was observed from the 30th of June to the 10th of September, even if few points had respiration values in the range of values generally observed for soil respiration for temperate ecosystems [12]. But significant higher values of respiration were observed on the 29th of September and October (p value < 0.05). The increase in soil respiration across the season was attributed to the maturation of crop residues and their gradual transformation from fresh organic matter to labile and dissolved organic matter, more easily degradable for microorganisms. It then appeared that the degradation process of cover crops passed through different phases; slow degradation until the senescence of the cash crop (here maize), then degradation inducing significant respiration. It seems that maize senescence leaded to favorable conditions for cover crop residuals degradation. Usually, when maize enters senescence, farmers stop irrigation to let maize dry before harvesting. Cover crop residuals could reach their optimum degradation rate with optimum both soil moisture and temperature promoting respiration of residuals in this particular time period. A second hypothesis is that maize plants senescence could imply microorganisms within maize rhizosphere to look for other sustainable carbon source when maize roots stop to diffuse exudates in soil [13,14]. These microorganisms could change of substrate when maize exudates stop and move from exudates to surface carbon.
Conclusion
TCover-crops constitutes a good solution to improve soil carbon content sequestration, both by increasing biological activities notably through biomass accumulation and exudation, and abiotic impact on cropland (temperature and humidity control). However, the production of supplementary biomass induces supplementary carbon fluxes from the agroecosystems that needs to be taken into account when assessing carbon footprint of croplands.
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Investigation and Comparison Effect of Glomus Intraradices and Glomus Mosseae to Control of Meloidogyne Javanica in Cucumis Sativus- Juniper Publishers
Cucumber (Cucumis sativus L.), from the squash family, which includes 90 genera and 750 species. Various factors reduce the yield of cucumber in different areas under the cultivation of this crop. Nematodes are important pathogens that cause great damage to agricultural products [1]. Plant root-knot nematodes are among the most destructive parasitic nematodes of various plants, especially cucumber. Different methods are used to control this nematode, but in most cases, their control is difficult due to the wide host range, short life cycle, and high rate of reproduction. Diverse organisms affect a variety of plant root-knot nematodes and reduce their population [2].
Mycorrhiza fungi are among the factors that reduce several plant diseases and can, directly and indirectly, affect the population of plant nematodes. Mycorrhiza fungi in nature in meeting the water and nutritional plant needs have an effective role and increase phosphorus, water, and minerals to increase plant growth and health. Much research has been done on the effect of mycorrhiza fungi on plant pathogens.
G. intraradices and G. mosseae are important in the interaction of pathogens with the host plant. They are released into the environment roots, soil and aerial parts of the plant in interaction with various other microorganisms survive. Species of this fungus, especially G. intraradices and G. mosseae to high reproductive rate, high ability in the use of different food sources, high power of aggression against pathogens, utilization of antagonistic mechanisms such as competition, parasitism, and antibiosis, ability to changes in the rhizosphere, production of extracellular enzymes such as amylolytic, pectolytic, proteolytic, lipolytic, Ketinolytic and cellulite as well as efficacy in stimulation growth and induction of resistance in plants are very important factors. More studies have shown that these fungi cause decrease diseases and symptoms are caused by soil pathogens [3].
Materials and Methods
Preparing M. javanica nematode population
After providing a plant sample infected with nematode, using single egg mass method, and reproducing it consecutively on the roots of cucumber, its purification and reproduction were performed. In most of the nematology investigation, the egg and larvae of nematode are used in order to create an infection. However, generally, because some eggs are not alive, using the second larvae of nematode is more common. Extracting egg and providing second larvae was done using [4] method.
Mycorrhiza fungi species preparation
Mycorrhiza fungi species G. mosseae, G. Intraradaices were taken from agricultural biotechnology laboratory and to investigate the effect of them in control of M. javanica in cucumber. Ingredients include vesicles, filaments, arbuscles, and fungal spores were mixed with sand. To mass propagate this fungus and obtaining the desired population from pure spores and disease-free, based on the advice of the method potting, was used in the greenhouse [5,6]. For this purpose, the fungi inside 5kg pots with a mixture of sand and clay in a ratio of five to one near the root of the cultivar corn single grass 704 stored and propagated for four months. The greenhouse conditions were controlled by day temperature and twenty-seven and nineteen degrees Celsius, respectively the relative humidity was sixty percent. After reproduction, for Ensuring the desired species and species, identification relying on the color scheme of the international collection of mycorrhiza fungi vesicles based at the University of West Virginia [7-10] finally, specifications species with descriptions of arbuscular mycorrhiza fungi compared and identified [11,12].
Investigation of the interaction of Glomus spp. on M. javanica nematode in greenhouse conditions
A total of six treatment combinations in the form of a complete random design in four replications in plastic pots one kilogram and one control were examined. Treatments include
a. Cucumbers inoculated with G. mosseae
b. Cucumbers inoculated with G. Intraradaices
c. Cucumbers inoculated with nematodes M. javanica
d. Cucumbers inoculated with G. mosseae and nematodes M. javanica
e. Cucumbers inoculated with G. Intraradaices and nematode M. javanica
f. Cucumbers inoculated with G. mosseae, G. Intraradaices and nematode M. javanica
g. A control.
Greenhouse environmental conditions during the maintenance period pots with a temperature range of 26 ± 2°C, sixty percent relative humidity, sixteen hours’ exposure period Irrigation was forty-eight hours a day and round. Eight weeks after inoculation of nematodes into the plants, the treatments were evaluated and indicators such as the number of nodes at the root, the number of egg and number of second instar larvae in the soil as well as reproduction index were calculated. Vegetative characteristics of the plant include root length, fresh and dry weight aerial parts, and roots were also evaluated.
Statistical analysis of data
Data analysis using statistical software, SPSS 20 analysis of variance of data and comparison of means with test Multiple LSDs performed at one and five percent levels.
Results and Discussion
Results of analysis of variance of the stem and vegetative traits roots related to infected cucumbers root-knot nematode M. javanica with fungi G. Intraradaices and G. mosseae were treated, shows that the effect of inoculation of treatments for all traits the study is significant at the level of one percent (Table 1) As in the table of comparison of mean traits vegetative (Table 2) is observed, the most effective G. mosseae + G. Intraradaices + M. javanica treatments and in G. mosseae + M. javanica is observed. The plant has also been compared to the control. according to the results comparison of mean growth characteristics of cucumber, fungal inoculated treatments, G. mosseae even ratio untreated control treatment with nematode with higher growth were due to the improvement of plant nutritional conditions and increased absorption of minerals, especially phosphorus with, G. mosseae increasing plant growth conditions and plant tolerance to nematodes [11,13,14].
Reproductive traits of nematodes result of analysis of variance of reproductive traits of root-knot nematode M. javanica (Table 3) shows that between treatments in terms of four important traits of nematode reproduction, namely number of nodes per root, number of eggs per root, number second instar larvae in soil and nematode reproduction factor, there is a statistically significant difference at the level of one percent. With pay attention to the comparison table of the mean of the related traits reproduction of nematodes (Table 4) lowest productions of galls and Egg, as well as second instar larvae and reproductive factor respectively in G. Intraradaices and G. mosseae + M. javanica and G.mosseae + M. javanica with M. javanica treatment, have a significant difference in the level they were one percent.
Conclusion
Examination of the results of the fungal effect test of G. intraradices and G. mosseae on M. javanica showed that both fungi have a significant effect on reproductive characteristics M. javanica. Due to the interaction of fungi and nematode with the plant, the amount of knot formation on the root and the number of eggs decreases. Therefore, the fungus may infect the plant defense system stimulates. Mycorrhiza fungi with the colonization of the rhizosphere environment prevent the spread of nematodes internal tissues take root. In the present study, among the two fungi tested, G. mosseae had a greater inhibitory effect. In roots colonized by fungi, G. mosseae enzyme chitinase increases. It causes the chitin to break down the nematode egg wall and eventually destroy it becomes an egg.
Also, the increase of arginine in the plant, from prevents nematode reproduction, and on the other hand with increasing the amount of phenol in the root reduces nematode proliferation and egg bag production and number of eggs. According to the report Smith this fungus has a lot of competitive power and has the power of colonization is high on the root system Smith 1988. Therefore, it can be justified that G. mosseae with the same competitive system has been able to significant growth and development of nematodes in the roots and consequently, in inoculated treatments with G. mosseae nematode reproductive factor significantly has decreased.
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Creation of New Lupin’s Forms with Economically Useful Traits- Juniper Publishers
Research materials were represented by the lupin collection of the Vavilov Institute of Plant Genetic Resources (VIR) storing now more than 2500 accessions of different lupin species collected by numerous expeditions over the globe and material from the All-Russian Institute of lupin. We have used the special methodology of the Vavilov Institute developed concerning lupin [1]. The same set of accessions was studied in different climatic zones of Russia, Ukraine, Georgia, and Finland using the same method. The theoretical basis for our research activities was N.I. Vavilov's works on plant genetic resources: the doctrine about the species as a system, the law of homological series in hereditary variation, differential systematic and geographical method of crop studies, etc. [2,3]. Many years of observing plants sown in various regions of many countries have enabled us to find out new regularities in the variability of characters depending on genetic features of the species and accessions, and on ecological and agronomic conditions of their growth. Geographic plantings and plant genetic resources study in different environments by uniform methods organized by NI Vavilov appeared extremely fruitful. They allowed obtaining valuable materials by hybridization between forms with different variability of characters in different conditions, which often proved the non-allelic nature of the genes controlling them, and consequently to produce transgressive forms. The nature of the variability of characters changes almost identically in most accessions when they are cultivated under different conditions. However, there are also samples of the character of variability in which is different in contrasting conditions (different geographic locations, soils, or different years of study). It is very important to identify such accessions and use them in further research. Studies have shown that when such accessions are crossed with each other, forms with new traits can appear in the hybrid generation, often useful or harmful for breeding. The hybrid progeny may contain transgressive forms, i.e., the forms with an increased or decreased value of the character when crossing parents with different types of variability. Differentiation in the variability of characters at parental forms can be found by testing them under different conditions and using the same techniques., It is possible to obtain valuable transgressive forms with the help of this method concerning any characters (high seed yield, chemical structure, disease resistance and others). Our approach makes the process of obtaining transgresses more controlled and effective. The positive results of increasing resistance to Fusarium wilt in lupin accessions were presented as an example in our previous work [4]. We have crossed samples with different variability of resistance in different test sites. As a result, two transgressive forms with increased resistance to Fusarium wilt were found suitable for the breeding program on Fusarium resistance in Russia, and Ukraine. These results served as an incentive for further research, because of which new forms with valuable traits were created:
a) Forms of yellow lupin (L luteus L.) with high protein content in mature seed (45 % and higher) were obtained by crossing cv. Borluta from Germany and k-1556 from Morocco.
b) Accessions of white lupin (L albus L.) with high protein content in mature seed (45 % and higher) were obtained by crossing k-298 from Palestine and k - 1538 from Poland.
c) Accessions of L albus with increased content of methionine (higher than 0.58 % to protein), by crossing k - 495 from Ethiopia and k - 828 from Germany.
d) Sources of high seed yield at white lupin (seed mass per plant 20.0 – 26.1 g), by crossing k - 2004 from Morocco and k-2521 from Portugal.
e) Forms belonging to the early group (101-115 days) were obtained by crossing cultivars Start from Russia and Tel Karam (k - 290) from Palestine.
f) Accessions described by increasing nitrogenase activity under artificial processing of Bradyrhizobium sp. (Lupinus) bacteria by interbreeding of cultivars Snezinka and Tambovsky 86 from Russia, k-1601 from Italy, and Leblanc from France.
New commercial cultivars of white lupin have been created at the All-Russian Institute of lupin based on the created by us source material: Aly Parus (Scarlet Sail), Michurinsky, and Pilgrim. Cv. Aly Parus has light pink flowers, an average growing season of 120-125 days (under the conditions of the Bryansk region of Russia), the seed yield is 3.8 tons per hectare, the protein content in the seeds is 34.5%. Varieties Michurinsky and Pilgrim are early ripening (110-113 days), productivity 4.0-5.0 tons per hectare, protein content 36.0 - 36.5%. Lupin is grown on an area of 60 thousand hectares in Russia.
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Hop Biomass Composting Approach Impact on Compost Microbiological Properties- Juniper Publishers
This sample study was used to take the snapshot of composts from hop biomass after harvest (stems and leaves of hop plants after hop cones harvest) and to start forming composting guidelines for hop growers to create quality compost for arable land. Each of three composting piles was prepared right after hop cones harvest in Sept. 2020 in a trapezoidal shape with a height of 2 m from 15 tonnes fresh biomass each. Differences among piles were in the size of the particles that the biomass was cut to, in coverage, in composting additives and in the number of pile turnings. We have reviewed the microbiological aspect composts after 7 months of composting. The microbial world of composted hop biomass solely (no other biomass added) is dominated by bacteria. In general, all composts lack diversity, which is main property of quality compost. The number of colonies forming units was in the range of expected, nevertheless, this unit has to be taken with precaution. PDA media stimulates growth of fungi and yeasts, therefore compost with effective microorganisms added at start, the smallest particles and foil cover after 1 month had the highest CFU on this media due to yeast fermentation. Fast changing conditions in soil demand fast adaptation of microbes that can only be tackled by diversity. The work on the topic will continue.
Keywords: Compost; Composting; Hop biomass after harvest; Humulus lupulus L; Microbiology; Diversity
Introduction
A primary objective of composting is to create efficient nutrient cycles in which nutrients from plant waste are effectively recycled into new plant biomass. During hop harvest, plants are cut and the whole aboveground biomass is taken from the fields. While cones are harvested, dried, and packed for brewing industry, stems and leaves (hop biomass after harvest) are left next to the harvest machine as a by-product. There are about 23,000 tonnes (15 tonnes/ha) of excess hop biomass (leaves and stems) produced in Slovenian hop fields each harvest season [1]. Although new ways of using hop biomass after harvest are being investigated, such as use for its antioxidant and antimicrobial activity for example [2], composting is still the most expecting way to use this biomass. Chemical composition of hop biomass is suitable for composting, especially when biodegradable twine is being used for hop support [3]. The ratio between carbon and nitrogen is 13: 1 when composting stems and leaves together and 23: 1 when composting only stems. Final compost (dw) contains about 3-4 % nitrogen, 0.3-0.4 % phosphorus, 1.0-2.5 % potassium, 35-43 % total organic carbon [4]. Microbes are responsible for the biochemical degradation of the organic litter and convert nutrients from organic to plant available, mineralized forms [5]. More than 90 % of all nutrients pass through the microbial biomass to higher trophic levels [6]. Many factors such as oxygen content, moisture, composition of the feed, pH, and temperature, affect microbes and consequently composting process. For that, compost chemical composition should be supplemented by microbiological overview [7]. Microbes are present in the environment. On average, 1 cm2 of plant leaf is covered by 106-107 bacteria [8], therefore the plant material itself present their source. If composting occurs on the soil, the soil also presents the reservoir of biological degraders which come to the compost pile. Composting induces high metabolic activities of many microorganisms (up to 1012 cells/g). The constantly changing conditions (temperature, pH, aeration, moisture, availability of substrates) results in stages of microbial consortia [9]. The initial decomposers are mesophilic organisms (bacteria and fungi). In the next stage, thermophilic organisms appear, especially actinomycetes, and the fungal populations decline. The final phase of composting is characterized by the development of a new mesophilic community; the actinomycetes remain and the fungi reappear along with cellulose-decomposing bacteria [10]. Soil compost amendments contribute to the general soil quality recovery and improvement of plant growing conditions [11] by providing numerous ecosystem services, including replenishment of soil carbon stocks, increase of microbial activity and biodiversity, and restoration of plant nutrition [12]. It has been demonstrated, that supplementing the soils with fungal or bacterial antagonists can reduce incidence of diseases in different crops [13-15]. There are various methods for assessing microbial picture of the compost; however, none of them is capable of perfect insight. Moreover, due to fast reproduction of bacteria in ideal environment, the population size is not as important as diversity and adaptability whereas in fungi, the size of organism can have greater impact [16]. In this study, we have reviewed the microbiological aspect of hop biomass composts after 7 months of composting. This insight will contribute to emerging guidelines for composting hop biomass after harvest solely, and to find the most suitable end use of the hop compost.
Material And Methods
Pile formation, weather conditions, process of composting and sampling
Composting experiment was performed between September 2020 and April 2021 in Lower Savinja Valley, Slovenia (Žalec; coordinates: 46.250997, 15.163939). Each of three composting piles was prepared right after hop cones harvest in September 2020 in a trapezoidal shape with a height of 2 m from hop biomass after harvest from 1 ha of hop field (approximately 15 tonnes each). Difference among piles was in the size of the particles that the biomass was cut to, two piles were uncovered all the season and one was covered after one month. There were no additives on the first compost pile, in the second we added biochar and in the third effective microorganisms (Table 1). Regular temperatures measurements were performed in the first two months and piles were turned when temperature was above 65°C; the number of needed turnings is presented in (Table 1). The piles were monitored during the degradation process and sampled for different analysis after 7 months of composting. Day precipitation amount and average daily temperatures in Žalec in the time of composting are presented in (Figure 1) [17]. There were a lot of rainy days in the last week of September and in the first half of October, with 9.7 mm average precipitation amount of rain per one day (Figure 2). In contrast, there was almost no rain from 17th October to 15th November. In December, there was much higher amount of precipitation on average in comparison to the 30-years average. Average daily temperatures were comparable to 30-years average only February was significantly warmer (Table 2).
Microscopy
Samples for microscopy were taken in triplicates, each from 4 different points in compost in April 2021. 1 ml of homogenized sample was placed in 15-ml tube and tab water was added to reach 5-ml mark. Tube was slowly inverted 30-times and left 1 min to settle. One drop of solution was placed on a slide and checked under light microscope for nematodes, flagellates, and ciliates, amoebas, bacteria, and fungi.
Total number of bacteria and fungi
Each sample was taken from 4 different points in compost. All samples were analyzed in duplicates. 50 g of sample was mixed with 200 ml of water. Ten-fold serial dilutions were prepared and applied to PDA and TSA plates. Plates were incubated for five days at room temperature before counted.
Microbial respiration
Microbial respiration was measured by Oxitop® system. Samples were taken in triplicates, each from 4 different points in compost. A fresh compost (20 g of dw) was placed in a jar with a cup of 10 ml 25-% NaOH and incubated for 5 days on 22°C. Pressure drop was measured every 24 min and was converted into O2 consumption by ideal gas law equation.
Results And Discussion
Microscopy
First notice of the compost under light microscope was bacterial predominance. Despite their abundance, the diversity of shape was poor. In general, the most biodiverse compost was compost 2, followed by compost 1 and compost 3. Composts 1 and 2 had many amoebae, while compost 3 lack these organisms. Bacteria are preyed upon by protozoa and nematodes, while fungi are preyed upon amoebae, nematodes, and micro-arthropods [18]. In soil, additional mineralization of microbial grazers is important when mineralization by microbiota is insufficient to meet plants requirements [19]. In general, composts lacked fungi that are important for breakdown of complex molecules and reabsorption of the nutrients [20]. Compost 2 had many spores that might activate when right conditions are met, while none was found in compost 3. When assessing fungal presence, the biomass ratio between bacteria and fungi must be calculated, as bacteria are single-celled organisms while fungi are multi-celled organisms that grow rapidly and in great lengths [20]. The biomass ratio between fungi and bacteria was 0 :1 as fungi hyphae were only found in traces. Fungi are aerobic organisms, therefore could not be found in compost 3 where anaerobic degradation or fermentation took place. Low presence of fungi in composts 1 and 2 can be linked to frequent turning of the compost that might have disturbed the hyphae growth. Bacteria are capable to grow and adapt more rapidly to changing environmental conditions as compost is than larger, more complex microorganisms like fungi. All composts contained Oomycetes that cause most of the soil-borne diseases [21]. Lack of microbial diversity can give opportunity to pathogens to attack plants and cause disease.
Total number of bacteria and fungi
The most dominant populations of the composts were bacteria, with the most cultivable cells in compost 3 that also had the greatest number of fungi, but mostly due to presence of yeast as fermentation process took place in this pile (Figure 3). Compost 2 had the fewest number of bacteria and fungi. The problem, however, is that despite their viability, only a minor fraction of the microbes can be cultivated [22] have detected 21 x 106 CFU/g of green waste compost on TSA, like count of our compost 3 and [23] about 1 x 106 CFU per g of dw of compost from biowaste. Compost 3 had almost 20 times more bacteria than compost 2 and six times more than compost 1. Compost 3 had added effective microorganisms at the beginning of the process and had the lowest temperature during the degradation process, whereas compost 2 had the highest temperatures that might reduce bacterial populations. Compost 3 had the least diverse fungi population, as yeasts were dominant. Nevertheless, CFU is commonly used unit it cannot predict microbial effect in rhizosphere [16].
Microbial respiration
Compost that is no longer undergoing rapid decomposition and whose nutrients are bound is termed stable; unstable compost, in contrast, may either release nutrients into the soil due to further decomposition, or it may tie up nitrogen from the soil. Its microbiological component determines how the compost will perform as a soil inoculant and plant disease suppressant [9]. Oxygen consumption increased linearly in 5 days for all samples. Compost 1 had the highest variability between triplicates (CV=23 %), followed by compost 2 (CV=16,6 %) and compost 3 (CV=10.5 %). The highest oxygen consumption in 5 days was for compost 3 (7.6 mg O2/g dw), followed by compost 1 (7.2 mg O2/g dw) and the least in compost 2 (5.5 mg O2/g dw). Compost 2 and 3 statistically different, whereas compost 1 overlaps with both (Figure 4). Slovenian standard for 1st class compost is respiration bellow 15 mg O2/g dw in 4 days. It is suggested that for horticultural applications, <20 mg O2/kg compost dry solids /h is considered stable. For field applications, <100 mg O2/kg compost dry solids /h is considered sufficiently mature (Insam and De Bertoldi, 2007). By these parameters, tested composts are considered stable.
Conclusion
This sample study was used to take the snapshot of composts and to start forming composting guidelines for hop growers to create quality compost for arable land. Compost must provide suitable environment for plant growth as it is used as amendment to the soil. The microbial world of composted hop biomass solely (no other biomass added) is dominated by bacteria. Bacterial dominated soil correlates with historic origin of lower plants, while fungal dominated soil correlates with succession of higher plants. If these composts were used for hop plants, more fungi would be preferable. Part of mycelium was found only in compost 1 and 2. In general, all composts lack diversity, which is main property of quality compost. The number of colonies forming units was in the range of expected, nevertheless, this unit must be taken with precaution. PDA media stimulates growth of fungi and yeasts, therefore compost 3 had the highest CFU on this media due to yeast fermentation. Fast changing conditions in soil (heat, drought, moisture, lightness) demand fast adaptation of microbes that can only be tackled by diversity. Due to their fast reproduction, the number does not play such important role as their diversity. The work on the topic will continue.
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Low Chilling Requirement Apple Cultivars as a Potential Genomic Resource for Improving Heat Stress Tolerance During Global Warming- Juniper Publishers
Climate change-induced global warming is projected to continue [1] and negatively affect various annual as well as perennial crops [2,3] Many deciduous trees require a specific cold period, for dormancy bud break, flowering and fruiting, together termed chilling requirement. Species with High Chilling Requirements (HCR), such as apple (Malus x domestica - MD), which is an important global crop, are expected to experience higher levels of damage and suffer more than other species with low or no chilling requirements. During rises in temperature, MD are likely to suffer from damaged reproductive processes, particularly dormancy release of floral buds, pollen/stigma interactions, fertilization and fruit development [4,5]. In the past, an “escape strategy” was successfully practiced in warm regions where most of the apple production was relocated from the hot valleys, up-hill to cooler environments. This strategy, which is still an option for coping with heat, seems to be less relevant for the future due to the above-mentioned predictions that even cooler regions will warm up. Thus, alternative solutions need to be developed.
Genetic Solutions
Here we present that adopting a genetic approach will be more promising and beneficial for the long run. This approach will exploit the natural variation of heat tolerance capacities that exists among different genotypes of MD that inhabit various environments which experience different grades of heat. Throughout the years, extensive breeding efforts yielded apple cultivars with Low Chilling blooming Requirements (LCR), which can successfully bloom in regions with relatively hot winters [6]. Since several of these commercial LCR cultivars, (such as "Anna," "Ein-Shemer," and "Dorsset-Golden") includes one parent of Middle Eastern origin [6], we hypothesize that their genome is adapted to hot and dry climates. Therefore, these genomes can potentially serve as genetic resource for identifying specific LCR genes which are associated with the response to HS. These genes are predicted to provide novel genetic tools which will lead to improvement of HS tolerance in apple during climate change conditions. In order to be able to utilize these genetic tools, a comparative characterization of the HS response in HCR and LCR cultivars is required. Below (Figure 1) is a schematic example of how we may achieve a collection of tools comprising Phenomics, Transcriptomics, Proteomics, Metabolomics and computational science for improving HS tolerance in apple. The knowledge gained by mining the suggested database can be translated through classic breeding or CRISPR based genome editing [7] into development of new heat tolerant MD cultivars, which will increase farmers’ ability to successfully cope with the foreseen heat challenge.
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Mediterranean Diet and Food Technology: Sustainable Strategies for A Globalized World- Juniper publishers
Mediterranean Diet has been widely studied and its nutritional, healthy, and sustainable benefits have been recognized. However, in the last decades, globalization has brought about major changes in the developed world and a progressive deviation from the main Mediterranean patterns. Fresh food and traditional recipes continue to be valued and their beneficial effects on health are scientifically proven. Despite this, they have been largely replaced by fast and less nutritious food is it possible to perform alternatives and procedures that help us to mitigate some deviations from the Mediterranean Diet, contributing to a more right, sustainable, and nutritious food system in a globalized world? This communication reinforces the idea that food technology and scientific advances must be properly applied to meet the challenges faced by Mediterranean countries.
Keywords: Mediterranean Diet; Food functionality; Sustainability; Consumption patterns; Food technology
Introduction
Mediterranean Diet implies not only the intake of certain foods but also a lifestyle with consumption patterns and relationship with the environment, that has been transmitted from generation to generation. It has been widely studied and its nutritional, healthy, and sustainable benefits have been proven. Its recognized global value meant the recognition of the Mediterranean Diet as Intangible Cultural Heritage of Humanity by the UNESCO Intergovernmental Committee in 2009 [1]. Moreover, it was recognized in 2019 as a possibly universal model of healthy diet from the EAT-Lancet Commission [2]. Regarding the food diversity, its processing and culinary procedures, the main nutritional, and sustainability advantages mainly derive from:
a. The use of crops and varieties adapted to local conditions. The growth of a wide variety of fruits, vegetables, cereals, and legumes prevails, and a wide heritage of ancient varieties have been preserved.
b. Fruits and vegetables are harvested at the optimum maturity, taking advantage of the maximum nutrient content. This fact is linked to a lifestyle in which social values and the care for the land and the environment predominates.
c. Fruits, vegetables, cereals, legumes, meat, and fish are integrated and combined in traditional recipes that complement nutrients and are cooked using simple techniques such as simmering, baking, dehydration, and fermentation. Mediterranean culinary system is part of the Mediterranean lifestyle and consumption patterns.
However, in the last decades there have been worldwide important changes that have brought with them a progressive deviation from the main Mediterranean patterns. The high population density in the cities and the depopulation of rural areas have reduced the availability of plant-food and increased the consumption of animal protein above the amounts needed for a proper nutrition. International companies have emerged increasing food availability around the developed world and the globalization of markets has occurred. The economic interests of large companies prevail over the reduced familiar economy. Consequently, it is no longer harvested at the optimum maturity since the food needs to withstand transport and distribution and reach the consumer in good condition. A huge number of residues are generated. Families no longer have time to cook traditional dishes while companies have technology to produce tasty dishes. Nevertheless, traditional recipes continue to be valued and their beneficial effects on health are recognized more and more. Sustainability and functionality of food are sacrificed and climate change and non-communicable diseases (obesity, diabetes, hypertension…) are exacerbated. An environmental, social, and nutritional alarm is created while the technological revolution reaches its highest levels. In this context, governments implement actions to prevent disasters without harming the patterns of economic development achieved by rich countries. It is promoted the consumption of vegetable proteins to reduce the emission of greenhouse gases; the consumption of foods with bioactive components with a health benefit; the reduction and valorization of waste and circular economy; the use of green and alternative technologies energy efficient, without effluents or chemicals. In addition, strict food regulations are established ensuring the highest levels of quality and safety ever achieved, but marked by abuses committed in the past, consumers increasingly distrust the food industry. Governments supported by scientific and technological development must find solutions to current challenges in a globalized world in which the recovery of social values and the integration with the natural environment requires combining Mediterranean values with economic development. Local agriculture and biodiversity must be promoted, and the social and cultural aspects must be respected. But is it possible to perform alternatives and procedures that help us to mitigate some deviations from the Mediterranean Diet, contributing to a more right, sustainable, and nutritious food system in a globalized world? This communication reinforces the idea that food technology and scientific advances must be properly applied to meet the challenges faced by Mediterranean countries.
Technology and Food Functionality
The technological and scientific revolution of last decades has not only provided safer foods with higher quality, but it has also allowed us to learn much more about the relationship among structural, compositional, and physicochemical characteristics of foods, the effect that processes have on them and their physiological use by the human organism [3]. This technological revolution is being properly used by many companies, which are very conscious of social and environmental problems. For example, certified B Corporations are a new kind of business that balances purpose and profit. They are legally required to consider the impact of their decisions on their workers, customers, suppliers, community, and the environment. This is a community of leaders, driving a global movement of people using business as a force for good. Nutritional and healthy effect of food is determined by its content in macro and micronutrients, their release at the target site in the adequate form and its suitable assimilation. These three aspects considered together define the functionality of a food and are reflected separately in digestibility, bio accesibility and bioavailability concepts. Nutrient bio accesibility is defined as the amount of the nutrient that is released from the food matrix and become available for absorption in the systematic circulation through the gut wall. Nutrient bioavailability considers the total amount of the nutrient that is released and absorbed to reach the bloodstream where it is delivered to the different body tissues. Besides them, digestibility applies specifically to the fraction of food components that is transformed into potentially accessible matter through all physical and chemical processes that take place in the lumen. Moreover, recently, the influence of nutrients in biochemical pathways through secondary metabolites produced by gut microbiota seems to be decisive in their healthy effect [4]. It is clear that fresh foods at optimum maturity have the highest content of nutrients and bioactive components but processing, especially heat treatments, decrease their content. However, in many fresh foods there are antinutrients or combinations of components that significantly decrease its nutritional value or may even make its intake unsafe. For example, phytic acid, lectins, phenolic compounds (tannins), saponins and enzyme (amylase and protease) inhibitors have been shown to reduce the availability of nutrients and cause growth inhibition, while phytoestrogens and lignans have been linked with infertility problems. Poor nutritive value of the food legumes is due to the presence of tannins that inhibit the digestibility of protein and phytic acid reducing the bioavailability of some essential minerals [5]. The case of iron is one of the most studied; bioavailability of iron is not only a question of its content, but also whether it is plant or animal derived and whether other biochemical factors are present within the food matrix [6]. In recent years, numerous studies have shown that the functionality of a food can be maintained and even increased with the application of simple technologies such as drying or fermentation. In most of legumes, soft heat treatments can improve the digestibility of proteins and carbohydrates. In the case of probiotics, Betoret et al. [7] have shown that when bacterial cells included in an apple matrix have been subjected to a controlled stress as a soft air drying at 50ºC, they better withstand storage at room temperature and the in vitro digestion process. In a similar way, Bass-Bellver et al. [8] obtained powdered food ingredients by freeze-drying or hot air-drying blueberry bagasse. Results showed that blueberry bagasse powders dried by hot air released more anthocyanins to the liquid phase after the gastrointestinal digestion in vitro, therefore, being more bioaccessible. In addition, alternative and also called green technologies have emerged. These are technologies such as ohmic heating, mild electric treatment or pressure treatments not generating effluents and energy efficient. These technologies make possible to reduce thermal treatments and even increase the functionality of some bioactive components or the digestibility of proteins. Many studies have been carried out to demonstrate that the application of HPH to liquid foods can modify the bio accessibility or bioavailability of its bioactive compounds. Treatment with HPH in mandarin juices increased the bio accessibility of total carotenoids by five times, although in the case of flavonoids, no such drastic changes were observed. Therefore, HPH treatment was recommended to produce tangerine juices that promote health, mainly through the improvement of the bio accessibility of the carotenoids contained therein [9]. Also, in legumes or cereals, the application of conventional processing techniques (e.g., cooking, autoclaving, germination, extrusion, and fermentation) to reduce or eliminate antinutritional compounds is well established. Nonetheless, such techniques, mainly those applying aggressive heat treatments, are often detrimental to other food constituents, so alternative green technologies that are applied under mild conditions are preferable.
Conclusion
The traditional Mediterranean Diet has a strong cultural and gastronomic background that facilitates its use as a tool for healthy food choices. The right foods are incorporated to tasty recipes that are eaten in a relaxed atmosphere of social relationship. People not only choose meals for their benefits on nutrition and health but also for their taste, palatability and social sense. Food technology and scientific advances show us how the low processing of some fruits, vegetables or legumes, the adequate treatment of wastes and bioproducts or the application of alternative technologies to typically Mediterranean foods allow a better exploitation and, in many cases, increase food functionality contributing to a more sustainable food system. Processed foods can combine the need for convenience, long shelf life and palatability required by consumers with the raw materials and nutritional principles typical of Mediterranean Diet. Furthermore, ingredients from by-products with a Mediterranean food design could be used to improve the adherence to Mediterranean Diet.
Moreover, these foods must be combined with the promotion of cultural and social values that are reflected in a lifestyle in agreement with the environment. Thus, foods produced with low processing taking advantage of the scientific advances and with a convenient (ready to eat) design, must be integrated into traditional Mediterranean recipes that allow: To balance nutrients, to keep on Mediterranean consumption patterns and to promote local varieties and cultural heritage.
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Use of GPS tracking collars on Sarda cattle in a Silvopastoral System- Juniper Publishers
Free-roaming Sarda cows grazing a Mediterranean silvopastoral area were fitted with Global Positioning System (GPS) tracking collars to estimate daily distance travelled (DT), daily (DW) and maximum distance (DWM) to water, and proportion of time (PT) the cows were near the water source, in different seasons and physiological status (dry and lactating). From a herd of 12 cows grazing 54-ha pasture, characterised by deciduous oak wood and glades, three cows (N=3) were fitted with Knight GPS collar during four sampling periods (one per season, from 26/02/19 to 16/10/2019). Collars recorded longitude, latitude, date, time, elevation at 3-minute intervals. DW and PT were calculated utilizing QGIS® (v. 3.16.3 “Hannover”). To compare DT, DW and DWM of dry and lactating cows across different seasons, the Aligned Rank Transform (ART) procedure was used, being the data were not normally distributed. The season affected (P<0.001) DT: the highest value was in Summer (7829±1305 m/day, median ± interquartile range), the lowest in Spring (4295±1617 m/day) and in Winter (4416±2487 m/day). Even DW and DWM were affected by the season: in Spring DW was 801±373 m, not different from the Autumn and Summer (709±126 m and 713±845 m, respectively), whereas cows stayed closer to water in Winter (570±135 m). Higher DWM was in Autumn and Summer (1328±130 m and 1310±98, respectively). Overall, the dry cows travelled more than lactating ones (7284±795 m/day and 4347±1845 m/day, respectively, P<0.001) moving further away from the water (DWM 1320±111 m and 1230±269 m, dry and suckling cows respectively) whereas DW was similar (710±122 m and 618±329 m, dry and lactating cows, respectively, P = 0.19). PT varied from 0.75% in Spring to 12.74% in Summer. These results represent the first findings concerning the Sarda cow grazing in silvopastoral areas.
Keywords: Low-cost GPS collar; Cows; distance travelled; Distance from water; Preference index.
Introduction
Livestock management on rangelands, with animals grazing extensive pastures, presents different challenges and an increased demand of labour than intensive livestock systems [1]. Understanding how cattle graze, how far they travel, and where they select to graze or rest can help the grazing management on rangelands since only an understanding of current grazing behavior can allow to manipulate the distribution patterns of animals. Moreover, the behavior in grazing livestock has an essential role in rangeland ecology. The distance pastured animals walk depends on many factors as size of the grazing area, the grass availability, the proximity of drinking water and management strategies [2]. Most of the problems associated with grazing animals in extensive rangeland pastures are related to their uneven patterns of landscape use. Cattle select locations on rangelands based on abiotic (e.g., topography) and biotic (e.g., forage quality) factors. Some of the most important factors that influence cattle grazing locations are distance to water, ease of travel, and amount of preferred forages. Farmers can improve distribution and grazing locations to more efficiently and uniformly utilize their forage resources by e.g., increasing water developments [3]. Global Positioning System (GPS) technology provides researchers with a tool to track cattle locations grazing distribution and activity. Advances in GPS technology create a consistent and accurate data source for individual animal locations over extended periods of a grazing season. Actually, livestock movement patterns can be monitored on a 24-h basis with GPS collars, with large amounts of animal location data over short sampling intervals and large spatial scales [4]. GPS tracking data can be to quantify the distance animals travel each day and to help estimate energy expenditure [3,5]. Indeed, foraging activity increases energy requirements of grazing animals and the estimates of this increase may range from minor to 50% [6]. The primary limitation to this technology was the cost of commercial GPS collars (from $1,500 to $2,000 per collar, 7) [8], developed a GPS collar that was less expensive (less than $1,000 USD) than commercial collars and, recently, low-cost GPS data loggers have been used to build unexpensive tracking collars ($150 to $300, 9) [9], removed excess weight from the device and added a larger capacity battery. It is important to note that these inexpensive GPS units do not have extra sensors built in, such as accelerometers, thermometers, or radio telemetry antennae used to locate the devices. This work is part of a long-term research project (iGRAL - Innovative beef cattle Grazing systems for the Restoration of Abandoned Lands in the Alpine and Mediterranean mountains) which aims at finding solutions to dramatic agropastoral abandonment of Italian mountains. Within this framework, free-roaming Sarda cows grazing a Mediterranean silvopastoral area were fitted with Global Positioning System (GPS) tracking collars to estimate the daily distance travelled (DT), the daily distance to water (DW), the maximum distance to water (DWM) and the proportion of time (PT) the cows were near the water point, expressed through a preference index (PI), in different seasons and physiological status of cows (dry and lactating).
Materials and Methods
Measurements and samplings
This study was conducted in an experimental farm of the Agricultural Research Agency of Sardinia (AGRIS Sardegna) located in Macomer (40°14’10’’N, 8°42’31’’E.) at 690 m a.s.l. It was conducted in compliance with the principles and specific guidelines on animal care and welfare as required by Italian law (Gazzetta Ufficiale, DL no. 116, January 27, 1992). The study area (ca 54 hectares) is characterised by deciduous oak wood, dominated by Downy Oak (Quercus pubescens Willd.), and glades with predominance of Pteridium aquilinum (L.) Kuhn. The remaining patches are composed by rock and herbaceous cover. The study pasture consisted of quite gentle terrain with an average elevation of 695 m (range 730 - 660 m) and average slope of 10.7% (range 0.5% - 36.3%). No extreme temperature or precipitation events occurred during the duration of this trial. The climate is Mediterranean with hot, dry, sunny summers and mild and rainy winters with some days of snow (average maximum temperature Tmax = 29.6; average minimum temperature Tmin = 1.9; total annual rainfall = 688 mm, https://it.climate-data.org/europa/italia/sardegna/macomer-14513/). Within the study area there is only one water point, located in the southern part of the study area. During the experimental period (from January to October 2019) the area was grazed by a cattle herd (N=12, 430±62 kg average live weight±s.d.), paired with their calves from calving period (October-November) to weaning (June-July). The cows belonged to Sarda breed, a small-to-medium-sized local breed, which is widespread throughout Sardinia and well adapted to the harsh environment of its hilly and mountainous areas. The beef livestock system in Sardinia is based on a suckler-cow system and calf production: the cows, mostly belonging to local breeds as Sarda cattle, crossed with specialized beef breeds (Charolais and Limousine), graze all year around in the mountain and hilly areas of Sardinia. The calves, weaned at about 6-7 months old, are sold mostly to the fattening centres of Po valley (Pianura Padana, in the North of Italy) for intensive fattening and commercialization [10]. Three cows (N=3) were randomly selected from the herd and fitted with modified igotU GT-600® GPS collars (Knight GPS collar, 9) during four sampling periods (one per season): from 26/02/19 to 03/03/2019 (winter), from 06/04/19 to 18/04/2019 (spring), from 16/07/19 to 24/07/2019 (summer) and from 26/09/2019 to 16/10/2019 (autumn). The cows from 26/02/19 to 18/04/2019 suckled their calves and from 16/07/19 to 16/10/2019 were dry. The Knight GPS collar uses the igotU GT-600® GFS unit and a recharge battery. Details are provided in [9]. The Knight GPS collars were placed on the neck of each of the tracked cows and were scheduled to record positions every 3 min. The fix rate was calculated for each collar, by dividing the number positions recorded by the scheduled number of fixes desired (480 positions every 24 h). Latitude and longitude coordinates were converted to the Universal Transverse Mercator coordinate system using a spreadsheet provided by the University of Wisconsin (http://www.uwgb.edu/dutchs/usefuldata/howuseexcel.htm) to facilitate calculation of distance travelled. Distance between two sequential positions was calculated using the Pythagorean theorem and then summed for 24-h periods to estimate distance travelled per day (DT). Average (DW) and maximum (DWM) daily distance from water and the estimate of the proportion of time the tracked cows were near the watering point were calculated using spatial analyst tools in the mapping program QGIS (v. 3.10.14 “A Coruña”).
Statistical analysis
To compare DT, DW, and DWM of dry and lactating cows and across different seasons, the Aligned Rank Transform (ART) procedure was used, being the data were not normally distributed. The ARTool procedure of R software version 3.3.2 (The R Development Core Team, 2016) was exploited to develop the model; the main fixed effects of physiological status of cows and season on daily Distance Travelled (DT), on average (DW) and maximum daily Distance from Water (DWM) were examined [11] and post hoc pairwise comparisons were conducted [12]. Animal was considered as random factor. Differences between treatments were determined by F tests. Tukey’s multiple comparison test was applied as appropriate to evaluate pairwise comparisons between treatment group means. Treatment differences with a P-value less than or equal to 0.05 were considered as significantly different, unless indicated otherwise. Preference Indices for water (PI) [13,14] were calculated for each season and physiological state of cows (dry and suckling). Preference indices were calculated as the proportion of GPS records in a buffer area of 20m. radius surrounding the water point divided by the proportional area of that buffer (ratio between buffer area and total experimental area). A 95% confidence interval with a Bonferroni adjustment [15] was calculated for each preference index to determine if buffer area was avoided, used indifferently, or preferred by cows. Values >1 for the lower confidence limit indicated preferential selection for a particular ecological group, while values <1 for the upper confidence limit indicated that cows used that buffer area proportionally less than its availability would suggest. If the value of 1 was within the confidence interval, it implied that cows were indifferent and used the buffer area in proportion to its presence.
Results
A total of 103199 valid animal positions were recorded during the deployment period. Average (± standard deviation) GPS fix rate was 94±2%. The average daily Distance Travelled (DT), the average (DW) and maximum daily distance (DWM) from water of cows in different seasons and in different physiological status (dry and suckling) are shown in (Table 1,2). The Proportion of Time the tracked cows were near the water point (PT) and the PI for water in different season and physiological status of cows are shown in (Table 3,4).
Discussion
The proportion of individuals fitted with GPS over the whole herd in this work was 25%. According to [16] behavioral assessment of few individuals, into of a group, may estimate the behavior of entire group. As a GPS fix was collected in 94% of attempts and standard deviation (7.2s) of the fixes was low, each point was accepted as representing equal time portions [17]. According to [18], in extensive system, each day grazing animals must decide where to graze, ruminate, rest, and drink. Large herbivore activity and use patterns in different areas are based on the kind of resources found there. Both abiotic (slope, distance to water, weather.) and biotic factors (forage quality, forage quantity, secondary compounds.) influence the way livestock use rangelands. Cattle and other large herbivores are central-place foragers with the central place or home place centered on water. Water is, therefore, the primary focal point around which the daily feeding and resting activities are arranged [18]. Distance to water have a strong effect on livestock distribution. As horizontal distance to water increase, utilization of an area usually decreases resulting in overuse near stock water and underuse at distances from stock water. [19] found that cattle preferred areas within 185 m of water and avoided areas greater than 600 m from water in mountainous terrain and, in general, preferentially use feeding sites nearest the stock water source. Using GPS technology, Ganskopp [20] documented the change in grazing patterns when the location of stock water was changed. This is because sufficient water must be available to animals in a specific area, given the current and expected climatic conditions. The DT values detected under our conditions (Table 1,2) are in line with the findings of Walker and Heitschmidt [21], which reported 5.8, 6.5 and 8.2 km/day with cows grazing 248-ha continuous pasture, 27-ha and 10-ha rotation pastures, respectively. Even [22] (heifers travelling 5.5 km/day in 4-ha rotation pastures and 6.1 km/day in a 20-ha continuous pasture) and [23] (Lidia cattle breed travelling from 2.2 and 4.3 km/day) reported similar values. However, [24] suggest that “an optimized rotational grazing system should be designed so that cattle do not have to travel more than 800 feet (ca 245 m) for water” but, they add “the guidelines for providing water extend beyond distance, however.” Distance to water appears to be the major factor controlling distance travelled, more than pasture size or grazing system [25,26] estimated that steers travelled 2.7 km/day in pastures where maximum distance to water was 640 m vs. 1.9 km/day where distance was 240m. [27] stated that 90% of grazing occurred within 3 km of well-watered paddocks. The authors claimed the correctness of calculating carrying capacity within a 3 km grazing radius in well-watered paddocks. Over this distance, very high utilization and poor land condition closer to water may result. The maximum distance to water values recorded in our work (Table 1, 2) seem to confirm the estimates of [26], taking into account the larger maximum distance to water detected in our conditions. Moreover, our DWM values have always been below the threshold value (3km) indicated by [27], suggesting our experimental area as well-watered. On the other hands, should be taken into account that accessibility of pasture, and hence its grazing capacity, progressively decreases as distance from water increase. This is because forage utilization has been found to decrease consistently as distance from water increase, leading to a graduated more than a uniform utilization of the vegetation [28]. The most important consequence of graduated utilization of vegetation is the fact that the amount of vegetation alone does not express a true grazing capacity value for a pasture. Size, shape of pastures and location of watering places are of utmost importance. Pastures could be well watered, have the same size and shape and contain the same kind and amount of vegetation and still could have different grazing capacities if water locations are considerably different. Water points centrally located in the pasture increase the grazing capacity of pasture [28]. In our experimental area, the longest DWM detected was 1328 m, hence, in line with [28] degree of grazing use would be below the 40%. This element is to be taken into account in the determination of a proper stocking rate. Ambient temperature, activity, and lactation status can all affect water requirements of beef cattle. Dry cows require 20 to 60 l of water per day whereas lactating cows require 38 to 80 l per day [29]. The greater water requirement of lactating cows and the behavioral requirements of caring for a calf can limit use of pasture [30,31] found that cows without calves graze further from riparian areas than cows that are nursing calves.
In the light of these general considerations, the longer distances travelled by the cows in summer and autumn (Table 1) and by nonlactating cows (Table 2) found in this work seem to have been due to three factors, mutually interacting:
a) In Sardinian beef livestock system, the calves are suckled by their mothers mainly until June. In the summer and autumn, therefore, the cows are nonlactating. The nonlactating cows are less hindered in their movement and use extensive pastures more evenly than cow-calf pairs, as also shown in the Tab. 2, where the longest distances covered by dry cows are highlighted.
b) In the summer the animals need to go to the water point more often. Moreover, during the experimental year, there were no rainfall events at the end of summer. The cows were therefore forced to increase the water point visits in autumn as well. In other seasons, animals can obtain water from other sources: the presence of snow during the winter may reduce the amount of water that livestock must drink. Water content of forages may be high enough in early spring so that cattle make minor use of stock water sources.
c) the longer distances covered in summer and autumn could also be linked to the forage quantity and quality at these times. When forage is abundant and of high quality, the time livestock spend grazing is reduced. As forage quality decreases, intake rates decline and grazing time increases, together with the distance travelled [32]. As expected, as the season progressed, the quality of the herbage deteriorates, according to a typical pattern of Mediterranean pastures [33]. Unfortunately, in a Mediterranean area such as Sardinia the herbage availability is abundant only for a few months in spring [34,35]. The longer distance travelled by cows in Summer and Autumn could be also due to the presence in the pasture, in these seasons, of flies (e.g. Hypoderma bovis). When face flies are a problem, cattle tend to select upland or open areas with more wind for resting. The animals are very bothered by these insects and tend to run away to try to shake them off, thus covering greater distances. The Preference index (PI), for the area of 20 m radius, surrounding the water point showed a selection of this area in all the seasons and by both lactating and non-lactating cows (Table 3,4). A marked seasonally variation in the selection was detected, with a stronger preference of cows for water point in Summer (Table. 3), confirming the findings discussed above. As expected, suckling cows showed a greater PI (Table 4), confirming their greater requirements for water [29]. These results show how the PI is to be considered an excellent synthesis tool for evaluating the grazing behavior of cows, allowing to detect preferred areas by grazing animals [36].
Conclusions
This work represents a first attempt to fill the lack of knowledge on behavior of Sarda cows grazing in silvopastoral area. Livestock’s environmental impact is frequently determined by livestock distribution; its knowledge can be an effective tool for reducing adverse impacts from livestock. An awareness of livestock needs and management is crucial for livestock producers, land managers, environmental interest groups, and policy makers. Distance travelled, distance from water and proportion of time the cows were near to water are crucial elements for a first understanding of the behavior of grazing cows. The advent GPS tracking has greatly enhanced the possibility of assessing these aspects and improve distribution and uniformity of grazing by livestock. The results of this work can allow:
i. A first estimate of energy expenditure for walking of Sarda cows in Mediterranean silvopastoral areas
ii. To evaluate the efficiency of water point distribution in the paddock and to point out the preference of cows for the water in different seasons and physiological state
The latter is the basis for hypothesizing the arrangement of portable stock tanks in grazed area or closing access to specific watering points in order to alter the distribution patterns of beef cattle on extensive pasture. This management practice may be used to 1) ensure more uniform use of forages across large pastures over time, 2) attract cattle to areas not habitually used, 3) temporarily lure cattle away from overgrazed areas, without the expense of fencing. Preliminary results are promising, but more research is needed to provide a real-time monitoring and management system (precision livestock management), able to improve livestock productivity and welfare.
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Trends on New Cooperage Toasting/Charring Technology TCT. Radio Frequency Volumetric Heating and Infrared Surface Toasting Principles and Application: Influence on the Heartwood Composition and Quality- Juniper Publishers
In the cooperage field, heating treatment represents one of the key step of casks production. First, heating is necessary to permit the binding of the staves and promote the general shape of the casks. In addition, it ensures the degradation of some polymers, such as polysaccharides and lignins, leading to the formation of various aroma compounds which directly contribute to the quality of the final product [1]. Consequently, the wood heating treatment directly impacts the diversity of composition and quality of both spirits and wines aged in these casks. In traditional systems used in barrel making process, heat energy is transferred from a wood fire (heat source) to the product (wood). In this case, it is necessary to heat materials for much longer times to ensure the interior of products be heated to an appropriate temperature, which in turn may bring about overheating on the surface of products. Indeed, conventional heating methods relies mainly on two heat transfer mechanisms, convection at the surface and conduction within the wood, which alternately have dominated effects at different stages during heating process. At the beginning of 1990 decade, some other systems appeared with gas heat or with electric heat system as a bread toaster. In the same time, several modern techniques were also developed using radio frequency probe for broad applications. In this context, two devices presented a high interest in cooperage: the Radio Frequency (RF) heating and InfraRed (IR) surface toasting. This system presented the main advantage to control with high fine tunings the toasting intensity, with maximum of consistency in the heat application to the wood. Thanks to a drastic decrease of the heat variability, a better homogeneity in the cask product was possible, leading to a reproducible cask’s composition, and thus a better control of the influence of wood on wine and spirit aging.
Brief of new Cooperage Toasting/Charring Technologies
Radio frequency heating
In contrast to conventional methods, RF heating, also known as high frequency dielectric heating, is a volumetric heating technique where electromagnetic waves (10 to 300 MHz) directly couple with the product, involving a direct transfer of electromagnetic energy. Thus, RF heating is different, since it heats at molecular level. RF treatment involves heating with electromagnetic waves. The heated product forms a “dielectric” between two metal capacitor plates, which are alternatively charged positively and negatively by a high frequency alternating electric field. three in other words, when the dielectric material (such as wood) with polarized molecules and charged ions is subjected to an alternating electrical field, one phenomenon that occurs is that positive ions within the material move towards negative regions of the electromagnetic field and inversely for negative ions, which is often referred to as “ionic migration.” In addition to the migration of charged ions, polar molecules, such as water, are forced to constantly align themselves appropriately with the electric field which is known as “dipole rotation” [2,3]. These phenomena lead to frictional interactions between molecules, resulting in heat generation. The interaction between wood and RF energy is also governed by the relative complex wood permittivity (i.e the ability of wood to store energy) and can affected by various factors, such as the frequency used, the wood density and moisture content [4].
Infrared (IR) Radiation Heating
IR radiation is based on the transfer of energy by radiation between the emitting source, made up of electric heating elements, and the heated product which absorbs all or part of this energy. IR radiation falls between the region of visible light and microwaves of the electromagnetic spectrum. It is propagated as a wave and gets converted into heat when interrupted by the food surface. According to wavelength, it can be distributed into three regions: near-IR (0.78–1.4 mm), mid-IR (1.4–3.0 mm) and far-IR (3.0– 1000 mm). Practically, products absorb IR energy most efficiently by changing the molecular vibrational state resulting in radiative heating. The exposure of IR radiation to the surface material results in its penetration into product, the radiation was transformed into thermal energy and the product is then heated intensely [5]. It was reported that IR heating results in high rate of heat transfer compared to conventional heating, and the product is more uniformly heated, resulting in better quality characteristics [6]. The macromolecular composition and structure of the product as well as the wavelength of IR radiation determines the depth of penetration IR radiation into the product. Although appealing because it is fast and produces heating inside the material, total energy absorption in IR heating is limited due to the inability of IR radiation to penetrate deeper inside the product [7]. Optimum use of energy through synergic effect may be obtained by combining IR heating with other forms of energy such as microwave or radio frequency modes of heating. Generally, solid materials absorb infrared radiation in a thin surface layer, but it was important to note that moist porous materials are penetrated by radiation to some depth, and their transmissivity depends on the moisture content [8].
Materials and methods
Generals
For this specific study, some experiments were performed in laboratories with small apparatus permitted the heat treatment of oak heartwood pieces. The 2x5 cm French oak pieces (Q. petraea from center of France or Tronçais forest) obtained from Demptos cooperage were used. Different Radio Frequency or Infrared programs (time, targeted temperature, or wavelength) were applied. The control sample corresponded to barrel toasted with traditional method by a wood fire. Two pieces of stave (2x5 cm) were chosen in the middle of the barrel after light, medium or heavy toast. The same procedure was carried out by infrared toasted of a 2x5 cm oak piece from the same wood pool used for the barrel production. Experiments were performed in triplicate. The TCT treatment was decomposed in two parts: first, the wood sample was heated until 130°C or 140°C by radio frequency in order to obtain the same effect as pre-heating before binding. Then and before temperature decrease, the second step of the real toasting by infrared radiation was applied. Infrared with short or medium wavelengths required 1 or 2 minutes to obtain light, medium, or heavy toasting, depending on the energy intensity. Radio frequency system reached the target temperature (130°C) in only few seconds. The toasting started when the temperature was maintained during few minutes. For the charring process, wood samples were toasted until the formation of a complete black layer with dense white smoke was observed, but before burning for laboratory security reasons. Liquid extraction was then performed after a 24-h period necessary to rebalance the temperature and humidity of wood sample. Each sample was extracted by 250 mL of acetone/water mixture (7/3, v/v) during 2 weeks in dark, at room temperature and under nitrogen atmosphere to prevent oxidation. Due to the large polarity of the solvent mixture used, a broad range of compounds were extracted. Solutions were then filtered, and acetone was removed by evaporation under vacuum at 35°C. Furanic, phenolic aldehydes derivatives and ellagic acid were then analyzed by liquid chromatography. For better clarity and concision of the data interpretation, only the main by-products issued from the thermolysis of the oak heartwood polymers were studied: hydroxyl-methyl-furfural from cellulose; furfural from hemicellulose; vanillin and syringaldehyde from lignins; and ellagic acid from C-glucosidic-ellagitannins. Only hydroxyl-methyl-furfural and vanillin were selected for global comparison (Figures 1-5).
Radio Frequency and infrared radiation heating systems
Experimental equipement, adaptated for laboratories investigation on small peace of oak, are provided by E.A Technology Ltd. (Capenhurst, Chester, CH1 6ES, GB).
LC-ES/MS analysis of wood aldehydes, furanics and pyranics compounds
HPLC/UV-Visible analyses were performed with a Waters separation module system, a Waters UV-Visible detector, and Millenium32 chromatography manager software. UV-visible spectra were recorded at 280 nm and 320 nm (for specific detection of phenolic aldehydes). The column was a reverse-phase Interchim C18 (10 m packing, 250 x 4.7 mm i.d.) protected with a guard column of the same material; solvent A, water/formic acid (98:2, v/v); solvent B, acetonitrile/water/formic acid (80:18:2, v/v). The column was placed at ambient temperature. The elution program was performed at a constant flow of 1 ml/min, passing from 5 to 30% of B in 40 min., and then rising to 40% of B in 10 min., and finally to 100% of B in 5 min., followed by washing and re-equilibrating the column during 15 min. The injection volume was 20l. MS measurements were performed on a LCQ ThermoTM instrument with an electrospray ionization source, in negative-ion mode with a spray voltage of 4.5 KV, capillary temperature: 275°C.
Pyrolysis-GC-MS experiment
A “PYROJECTOR SGE II” was used as pyrolyzer, in conjunction with a Varian 3400 CX model gas chromatography apparatus equipped with a Varian Saturn 4D ion trap detector. Samples (approximately 0.1-0.2 mg) were placed in the pyrolyzer and triplicate pyrolysis experiments were carried out at different temperatures: 300°C, 400°C, 450°C, 500°C, 600°C. General profiles for pyrolyzates were obtained using EI-MS. Separation of the pyrolysis products was achieved using a fused-silica capillary column: RTX-20 WCOT(30 m x 0.25 mm i.d x 1m phase thickness, 80% dimethyl and 20% diphenylpolysiloxane). Helium was used as the carrier gas at a nominal flowrate of 1 ml/min. The inlet mode was spitless. The gas chromatography oven was operated using the following programme: isothermal for 10 min at 50 °C, then raised from 50 °C to 280°C at 6°C/min. The mass spectrometer was set at 70 eV. Spectra were produced using a ChemStation software package. Identification was achieved by mass fragmentometry, by comparison of their mass spectra and relative retention times with those of compounds reported in the literature and the National Institute of Standards library (NIST). When possible, the identifications were accomplished by comparison with authentic standards. Quantification was based on peak areas (total integral of identified compounds equals 100). The syringyl/guaiacyl ratios (S/G) were calculated by dividing the sum of the peak areas of syringyl units by the sum of the peak areas of guaiacyl units.
Result
Preliminary results on radio frequency and infrared heated treatment of oak wood, comparison with traditional casks fire binding/toasting process. Preliminary results are presented on and. The effect of RF/IR heat treatment on wood pieces and the practical effect of traditional binding/toasting in cooperage were investigated. Only French oak was analyzed in this study and further research are required on different oak origins, especially on American oak. illustrates the impact of the various heating procedures on the content of HMF and vanillin, chosen as indicators of heat treatment. Regarding the untoasted oak (control sample), heat treatment promoted the formation of HMF and vanillin at different levels but always higher than in control. Interestingly, a global evolution of theirs contents according to the toasting intensity (light, medium, heavy toast) was emerged. Using either traditional binding/toasting in cooperage or with RF/IR heat treatment, same evolution trend was observed. For the first stage, both methods were similar, and combining RF and IR heat treatments well-reproduced the main impact of a traditional binding/toasting. More precisely, RF/IR heat treatment promoted a higher concentration of HMF and vanillin for each toasting level (LT, MT, HT), since the reaction was more intense than in the traditional binding/toasting procedure. The differences observed were significant and represented up to 25 to 50% higher concentration of the two assayed compounds for RF/IR heat treatment. Concerning the charring trial, visual aspect of the wood surface was very close to traditional charring with gas fire and corresponded to what expected for this kind of treatment. These results were in accordance with examination made by J.S Swan on this experimental sample (IR charring versus oven charring) and other samples issued from a real charring treatment in a Scotland cooperage. Consequently, a typical charring was also possible using RF/IR heat treatment. In our study context, charring promoted the degradation of the majority of the wood polymers such as polysaccharides and lignins, leading to higher concentrations in HMF and vanillin than heavy toasting. Surprising different results were obtained with an oven charring or gas charring. Indeed, the content of aroma compounds in these two last procedures was lower, especially for compounds issued from polysaccharides. RF/IR heat treatment allowed to reach, in the same time, the standard level of a visual charring, with conservation of a large amount of aroma compounds. In a second series of experiment, the specific effect of a pre-heated operation by RF system before the post-toasted treatment by IR was investigated. Interestingly, since the pre-heated treatment by RF was usually necessary for binding the stave, this operation also improved the aromatic compounds produced during the second heated treatment by IR. presents the effect of (i) RF treatment at 130°C (just before binding) following by the IR toasting, and (ii) RF pre-heating at 140°C, maintained at this temperature for 3 min and followed by the normal process of IR post-heating to obtain low, high, and medium toasting levels respectively.
This highlighted that the 3-min delay at 140°C significantly improved the thermolysis reaction with an increase of HMF and vanillin content in the treated oak samples. For low, medium, and high toasting’s, the variation of the concentration was impacted by a factor 2 and similarly concerned polysaccharides pyrolysis (HMF) and lignins pyrolysis (vanillin) products. It is reasonable to imagine similar observations about the melanoïdins formation and their main pyrolysis products, like maltol or cycloten (not confirmed in this work by specific experiments). After targeting an optimisation of pre-heated treatment by RF system, the IR heating treatment was then improved. A regular RF pre-heated (to reach 130°C) and a series of toasting with medium or short wavelength for 1 or 2 min were thus compared. Data revealed that (i) the exposition time to IR for 1 or 2 min increased the concentration of HMF and vanillin in oak samples and (ii) medium wavelength promoted all the pyrolysis reactions, with higher concentration of aroma products at the end of the heat treatment application. Higher content in HMF and vanillin was obtained for the procedure with medium wavelength during 2 min. An IR heating with medium wavelength option for 1 min represented thus a good compromise between time of treatment and balance of aroma compounds.
Finally, the reproducibility of the heating system was studied by comparing traditional fire binding/toasting and RF/IR methods. For both medium and heavy toastings, RF binding and IR toasting gave the best consistency in the production of HMF and vanillin (i.e lower variability in the content of these two compounds), suggesting best robustness of the RF/IR method than traditional one.
A first approach of the specificity of pyrolysis chemistry reaction for RF/IR heat treatment
An overview of pyrolysis reaction. According to the polymer composition of oak wood, various molecules formed by pyrolysis derived from polysaccharides, or carbohydrates and lignins. During pyrolysis, polysaccharides produced different furanic and pyranic compounds, such as 2-, 3- and 2,5-furfuraldehyde, 4-hydroxy-5,6-dihydro-(2H)-pyrane-2-one, 5-hydroxymethyl-2-furfuraldehyde (also called HMF, using as a key compound in our investigation) or hydroxymethyl-pyranone. The 2-, 3-, and 2,5-furfuraldehydes came from pyrolysis of the pentose units of hemicellulose, whereas the 5-hydroxymethyl-2-furfuraldehyde from the glucose units of cellulose. The ratio between the heights of m/z 96 (in pyrolysis/MS analysis) and 126 peaks was, on average, 1.9 ± 0.2 [9]. Although cellulose is more abundant in wood, hemicellulose is more easily thermally degraded. The main products originating from pyrolysis of lignins are classified as guaiacyl “G“units (monomethoxylated) and syringyl “S“ units (dimethoxylated). Among the G units, 2-methoxyphenol and 4-formyl-2-methoxyphenol (also called vanillin, using as a key compound in our investigation) were identified. Similarly, 4-vinyl-2,6-dimethoxyphenol and 4-formyl-2,6-dimethoxyphenol (syringaldehyde) were identified within the S-units. The S/G ration varied during the course of pyrolysis: 1.25 at around 150°C, 18 at 195°C, 2.2 at 220°C and 0.77 at around 250°C [9]. This result suggested that, for temperature below 220°C, pyrolysis degrades the S units of the lignins selectively whereas, at higher temperatures, the phenomenon is reversed and lignins, in G units, were more affected.
Cellulose, although much more abundant in oak than hemicellulose, is degraded less, whatever the temperature level. The crystalline structure of a part of the cellulose explains its resistance [10]. Using CPMAS 13C NMR, the proportion of crystalline cellulose in Q. robur and Q. petraea was present at 45% [11]. During pyrolysis, the furanic derivatives released by thermal degradation of arabinose and xylose were predominant. Depolymerization of lignins was high at temperature of around 150°C. Beyond this temperature, a sharp decrease was observed in the thermo-degradation products. In accordance with [12], the increase in temperature led to depolymerization at first, followed by cross-linkage of the lignin at higher temperature. The new polymers produced have higher molecular masses and fusion points. Careful examination of S/G ratio showed that the different kinds of lignins were transformed during pyrolysis. From 150°C to 220°C, the S/G ratio is greater than 1 and above 250°C, it becomes less than 1. During the first phase of thermolysis, the lignins located in the secondary walls, rich in S units, were degraded. At higher temperature, thermal degradation concerned more particularly the primary walls containing lignins rich in G units [13]. Some specificity of the RF/IR treatment in comparison with traditional fire toasting. Based on specific experiment, the practical aspects of pyrolysis chemistry for FR/IR heat treatment were studied in comparison with traditional fire binding/toasting. The heat treatment on main oak heartwood polymers, as well as cellulose, hemicellulose, lignins and ellagitannin composition, was evaluated. In both experiments and for all targeted compounds, RF/IR heat treatment gave more thermal degradation by-products: HMF, furfuraldehyde for polysaccharides; vanillin, syringaldehyde for lignins; and ellagic acid for ellagitannins. Concerning polysaccharides, effects were discriminated according to the nature of polymers. For cellulose, the more resistant form of polysaccharides to pyrolysis because partially crystallized, RF/IR promotes a large increase in the content of HMF (+72, +74%) the main key aroma compound derived from this polymer. In contrast, and although the quantity of specific by-products were higher by RF/IR treatment, hemicellulose (easily pyrolysis polysaccharide) presented a less answer to RF/IR treatment. Indeed, a limited increase (+11, +20%) of the furfuraldehyde concentration (key compound of hemicellulose) was noted comparing to traditional fire binding/toasting. This difference was clearly highlighted by the ratio HMF/furfuraldehyde comparison: 0.04-0.02 for traditional fire toasting and 0.11-0.06 for RF/IR treatment. Concerning lignins, the chemistry pyrolysis was not affected by the heating system, since a more or less similar ratio S/G was found using either traditional fire binding/toasting and FR/IR treatment: 2.8-3.0 for the first experiment and 2.2 for the second. However, and similarly to polysaccharides, the final concentration of by-products enlarged in a significant proportion (+61% to +71%). Finally, interesting findings were obtained for ellagitannins. In comparison to traditional fire binding/toasting, RF/IR treatment degraded a larger amount of ellagitannins, observable by the increase of ellagic acid (+65% to +77%), the mains stable by-product of C-glucosidic ellagitannins thermal degradation.
Discussion and conclusions
The aim of this study was to investigate a new generation of cooperage heat treatment by electric devices in order to substitute the traditional fire system. This study was conducted mainly to push-on the rate of casks binding and toasting in the industrial process. Radio frequency and infrared system appeared as a great compromise between the faster capacity to operate and their ability of mimic the global chemical process occurred during the traditional fire method. However, some differences were also observed, in favor to the RF/IR equipment. However, before anything else, several potential difficulties due to fast heating procedure needed to be clarified: The binding can promote the stave breakage, since we don’t take enough time to reach in the same time the plasticity of the wood (by temperature application), the repartition of the tension (surface tension of the lignins and the mains polymers) and the plasticity capacity homogenization on the whole volume of the staves material. To solve this specific problem, it was probably highly recommended to increase the duration of binding, from few seconds to a minimum of 20 seconds. Pre-moisturizing casks may help to reach this point. Another issue was the constant temperature repartition within the wood. Theatrically, in the FR and IR systems, the temperature was constant in every part of the wood in accordance with our program selection. However, wood structure, especially wood porosity, was not uniform and led to some change in the physical properties of the stave. Thus, this phenomenon has to be taken into account when a program of toasting was designed. This issue may also be an advantage when the variety of the toasting profiles was considered, that sometimes represented a part of the complexity of casks and the ageing quality. Concerning the specific point of toasting and aroma production, the RF/IR method clearly initiated a higher production of aroma compounds, even coming from some particular pyrolytic resistant polymers like cellulose. Better degradation of ellagitannins was also observed, resulting in a final low polyphenol impact of the cask and an improve of mouthfeel properties of aged wines and spirits. In comparison with traditional fire toasting method, the consistency and the reproducibility of the toasting, underlining by a lower variability in the content of HMF and vanilla, was also obtained using RF/IR treatment. Indeed, application of a specific program of treatment, such as pre-heating for few minutes (2-3 min) by radiofrequency at 140°C-150°C, enhanced the aroma compounds production. This was particularly useful to increase aroma potential of wood casks, preserve energy by a faster IR toasting or retreat old casks (5- 10- fill casks). This also facilitated the production of a minimum of aromatic compounds coming from pyrolysis of the residual polymers which were still active in aroma production. Overall, the RF/IR combination system as a binding/toasting system presents a high interest in the barrel-making process, due to the fastness of the cooperage facility, as well as the final product quality. Considering our first investigations, the application of this technique for industrial casks production was thus highly recommended.
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Irrigation System Distribution Uniformity Evaluations in the Pajaro Valley, California- Juniper publishers
The Resource Conservation District (RCD) of Santa Cruz County and the UC Cooperative Extension of Monterey County performed 25 distribution uniformity (DU) evaluations in the Pajaro Valley between September 2015 and July 2017 following a method developed by Dr. Mike Cahn from the UC Cooperative Extension of Monterey County. The evaluations were performed in collaboration with interested growers and resulted in reports with recommendations to improve the performance of the irrigation system. An estimate of the potential savings, in terms of water and costs, were also included in each evaluation. Funding for the project came from PVWMA and from DWR.
Distribution uniformity is a measure of how evenly water is delivered to the crop and is an indicator of the efficiency of the irrigation system. Less water needs to be applied for a system with a high DU to meet the crop demand than a system with low DU. By improving DU of the irrigation system water conservation can be achieved at the same time avoiding over‐irrigation, runoff and water logging.
Each evaluation consisted of pressure measurements taken at various points across the irrigation system, to evaluate the performance of the pumping station equipment, main and submain lines, valves and pressure regulators. In drip systems lead hose connecting the submain to the drip tape laterals and the drip tape performance were also evaluated. Catch-can experiments were performed in all evaluations, placing cups or bottles under the emitters in drip systems and setting a grid of buckets under sprinkler systems. Other indicators of the irrigation system performance and management were recorded, such as runoff and ponding produced by the irrigation, leaks, row orientation, system flushing, emitter plugging, nozzle wear etc.
The evaluated irrigation systems included drip tape, drip hose, pressure compensating emitters, micro‐ sprinklers and overhead sprinklers irrigating various crops such as strawberry, vegetables, ornamentals, caneberries, apple and wine grapes (Table 1). On each ranch, only a fraction of the total ranch area was evaluated, usually one or two irrigation blocks. The evaluated irrigation blocks ranged in side from 0.6 acres to 5.7 acres and totaled 82 acres. Ranches ranged in size from 3 to 100 acres and the area of all ranches combined was 700 acres.
Table 2 shows the recommendations resulting from the evaluations and the frequency of the recommendation. The most common recommendation was to install pressure checkpoint (Schrader valves) and to provide the irrigator with a handheld pressure gauge to check water pressure when operating the system. The second most common recommendation was to install pressure regulators to balance pressure between different blocks; this recommendation was very common in ranches with sloped fields. Plugged emitters were the third most common cause of poor DU, particularly in ranches where liquid organic fertilizer was injected in the system. Recommended practices to avoid plugging were: flushing tapes and manifolds after each fertigation and stopping the fertilizer injection at least 30 to 45 minutes before the end of the irrigation set to allow the fertilizer to be completely flushed from the drip lines. Fixing leaks and installing larger diameter oval hoses were the next most common recommendation for drip systems. In some ranches, pressure regulators were present, but the irrigator was not trained on how to adjust them or did not have a pressure gauge to measure the pressure. Thus, adjusting pressure regulators was also a common recommendation. Other recommendations included increasing the irrigated area instead of closing a valve to reduce pressure in the irrigation system, changing row orientation to lessen the slope of the rows, and improving maintenance of the filters.
When grouped by irrigation method, drip tape showed the highest average DU (83%) followed by drip hose with pressure compensating emitters (81%), sprinklers (76%) and the lowest was drip tape in organic production (75.5%) (Figure 1). However, the differences in DU were not statistically significant (P‐value 0.34, Table 3). In one case pressure compensating systems did not yield a better DU than traditional driptape, since the system was run at a pressure below the pressure‐compensating range of the emitters. Drip tape in organic ranches yielded poorer results than in conventional production, due to emitter plugging resulting from injecting organic liquid fertilizer, and because organic ranches are often located on marginal sloping land where differences in elevation affect the DU.
Table 4 summarizes the potential savings estimated for each ranch based on the measured DU, the target DU considered achievable for the ranch conditions, and the estimated average seasonal evapotranspiration of the crop. Potential savings in terms of volumes of water in Acre‐feet (Ac‐ft)/season were calculated for each ranch assuming that the grower would implement recommendations across their whole ranch, improving the DU from the observed to the target value. Monetary savings were also calculated based on PVWMA augmentation fees and average pumping costs. In some cases, the potential cash savings exceed the costs of the equipment needed to improve the DU, which would also result in indirect revenue for the farming operation due to less nitrogen leaching, increased yields, and regulatory relief. However, the total estimated potential savings for all farms evaluated was 149 Ac‐ft per season, which is a relatively modest savings, compared to PVWMA’s basin‐wide conservation target of 5000 Ac‐ft by 2035.
In some systems evaluated, the measured application rate deviated substantially from the design application rate (Table 5), with the measured application rate ranging from 63% higher, to 32% lower than the designed application rate. This deviation was observed regardless of the measured DU and was common even in fields with very high distribution uniformity. This occurred usually because the operating pressure was higher or lower than recommended by the drip tape manufacturer. Knowledge of the actual application rate is crucial to correctly schedule irrigation events. For example the first ranch in Table 5, although presenting a DU of 96%, would be under‐irrigating by 15%, whereas the third ranch, with a DU of 91% would be underirrigating by 19%. These results suggest that even very efficient system can be hindered by improper management.
A negative correlation was found between the slope of the ranch and the DU measured for drip systems and a positive correlation for sprinkler systems (Figure 2). The linear regressions were not statistically significant when the data was grouped by method (Drip and Sprinkler in Table 5), due to the significant scatter in DU for ranches without significant slope. When only drip system at ranches with appreciable slope (higher than 1.5%) was considered, the linear regression was significant (Table 6 & Figure 3). This correlation appears to be caused by the high variability of pressure caused by differences in elevation and highlights the importance of pressure regulators and adequate row orientation on sloped fields.
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Browntop Millet- A Review- Juniper Publishers
Browntop millet (Brachiaria ramosa (L.) Stapf; Panicum ramosum L.) is an introduced annual grass that originated in South-East Asia. It is grown in Africa, Arabia, China and Australia [1]. It was introduced to the United States from India in 1915 [2]. In the US, it is mainly grown in the South-East for hay, pasture and game bird feed. The browntop millet, called korale in Kannada, is specially grown in rainfed tracts of Tumakuru, Chitradurga and Chikkaballapura districts of Karnataka state. The crop is popular in this region in terms of cultivation and consumption. This millet seed is grown in a variety of soils and climates. Like other millets, it is a hardy crop and well suited for dry land.
Description
Browntop millet is an annual warm-season species that grows 1 to 3 ft tall. The smooth stems have pubescent nodes and may stand erect or ascend from a decumbent base. The leaves are 2.2 to 18cm long and 6-18mm wide; both surfaces are smooth. The inflorescence is indeterminate, open, spreading with simple axis and stalked flowers. It has 3-15 inflorescences and white flowers. Seeds are ellipsoid and tan in colour; they mature in approximately 60 days [3].
Uses
Forage/grain: Compared to other warm season forage grasses, browntop millet is relatively low yielding. Its strength is that it is a rapidly maturing grass, often used as a catch crop, cover crop or nurse crop [4]. Browntop millet can accumulate toxic/lethal levels of nitrate and should not be fed to livestock if the plant has been stressed by droughty or cold conditions. There is evidence of the cultivation of browntop millet as a subsistence crop in Neolithic India and it continues to be used as a grain and forage crop in India today [5]. Grains from taller nonshattering varieties are used as a boiled whole grain, porridge or unleavened bread [6].
a. Cover crop: Browntop millet is used to suppress root- knot nematode populations in tomato and pepper crops in the South-East [7]. It is grown as a fast-growing catch crop between commodity crops and is not known to be allelopathic.
b. Critical area planting: Browntop millet is used as a fast growing cover for erosion control. It is used as a nurse crop in the South-East until a perennial grass cover is established. It also has the ability to accumulate significant amounts of lead and zinc in shoot and root tissues making it an important plant for remediation of contaminated soils [8].
c. Wild life: Browntop millet produces large quantities of seeds. These millet seeds are used in food plots for game birds that are highly attracted to the nutritious seed. Browntop millet is one of the few types of millet that can be planted and flooded for ducks or planted in dry areas for deer, quail, dove, turkey and other wild life.
Cultivation
Planting time: Browntop millet can be planted from mid- April until mid August in most locations, though later plantings will result in lower yields.
Seed rate and planting: The seed rate for browntop millet will depend upon both the target species (birds & wild life) and the seedling method. Birds food plots are generally seeded at the rate of approximately 4-5kg per acre when planted in rows and 11-12kg per acre when broadcast. Seed should be covered to a depth of half inches in a firm seed bed [9]. Browntop millet can be used in combination with a variety of agricultural crops or other species planted for wild life. The species commonly planted intercropping with browntop are sunflowers, corn, sorghum, soybean, and peas. This method is ideally suited to larger fields, in which the millet is planted in alternating strips with other crops.
In Karnataka state, farmers popularly/locally called browntop millet as branched or chaduru korale and Round panicle/Dundu korale. Normally branched one has low pests and diseases, where as round panicle browntop millet give higher yields. They use the traditional drillers for sowing the seeds one inch below the top soil. This method is recommended for a better yield. Five kg seeds are required per acre. Seeds get germinate by the fifth day of sowing. Farmers get seven to eight quintal grains per acre and four tractor loads of good quality fodder. They consume grains by making roti or as rice. The crop matures within 60-70 days. The shelf life of seed is about five to six years, while the shelf life of browntop rice is only about 25 to 30 days [10].
Fertilizer
Fertilization with phosphorous and nitrogen can help increase forage productivity; rate of application should be determined by the results of soil tests and /or country recommendations.
Weed management: To control weeds, it is best to plant in a well-tillaged field, weed-free bed with narrow row spacing. Chemical weed control options are limited. It does not regrow well after cutting, so it is a one-cut crop.
Seed processing: The cultivation of browntop is simple but processing is difficult due to the hard outer cover of the seed. As a result, farmers get only 40-50kg of rice from one quintal of browntop/korale seeds. Earlier grinding stones were used to separate the grain from the seed. Today, grinding stones have almost disappeared and korale seeds are processed in the flour mills that process finger millet [10]. The size of korale rice is also very small and separation of stones is difficult. Hence, processing has become a bottleneck for farmers, and efforts are on to design improved processing machines.
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