Novel combination artificial neural network models could not outperform individual models for weather-based cashew yield prediction.
Cashew is an important cash crop which is ecologically sensitive, making it vulnerable to climate change. So, the present study compares the performance of stepwise linear regression (SLR), least absolute shrinkage and selection operator (LASSO), elastic net, and artificial neural network (ANN) individually against the ANN model combined with SLR, LASSO, elastic net, and principal components analysis (PCA) for prediction of cashew yield based on weather parameters. The model performances were evaluated using three approaches: (1) Taylor plot; (2) statistical metrics like coefficient of determination (R2), root mean square error (RMSE), and normalized RMSE (nRMSE); and (3) ranking followed by Kruskal-Wallis and Dunn's post hoc test. The results revealed that during calibration, the R2 and RMSE ranged from 0.486 to 0.999 and 2.184 to 88.040 kg ha-1, respectively, while RMSE and nRMSE varied from 3.561 to 242.704 kg ha-1 and 0.799 to 89.949%, respectively, during validation. Kruskal-Wallis and Dunn's post hoc test revealed LASSO as the best model which was at par with ELNET, SLR, and ELNET-ANN. So, these models can be used for cashew yield prediction for the study area well in advance. https://doi.org/10.1007/s00484-022-02306-1
State-led agricultural subsidies drive monoculture cultivar cashew expansion in northern Western Ghats, India.
Agricultural commodity production constitutes an important livelihood source for farmers but significantly contributes to tropical deforestation and biodiversity loss. While the socioecological effects of agricultural commodities such as palm oil, cocoa and coffee are well studied, the effects for commodities such as cashew (Anacardium occidentale) have received less attention. Global cultivated area for cashew increased rapidly from 526,250 ha in 1980 to ~5.9 million ha in 2018. India is the world's second largest cashew producer, with cashew farms often occurring adjacent to remnant forests. To mitigate deforestation for cashew expansion, it is necessary to understand present-day land use policies and management practices that drive this expansion. Through semi-structured interviews (n = 65) and a literature review on agricultural policies in India, we evaluated the role of state-led land use policies in cashew expansion and characterised present-day cashew farming systems in the Sawantwadi-Dodamarg landscape in India. Agricultural subsidies introduced from 1980s to 1990s encouraged cultivar cashew expansion and influenced land use conversion from rice and privately owned forest to cashew. Farmers preferred cultivar cashew as they produced higher yields faster, although they required more agrochemical inputs and were susceptible to pests and wildlife depredation. About 80% of farmers had planted cashew farms by clearing forests in the past 30 years and expressed interest to continue the same. Farmers avoided applying for government-sponsored compensation for crop losses due to wildlife depredation and chose instead to expand cultivar cashew into forested areas. Our study deepens the understanding of how government-led agricultural subsidies drive farmers' uptake of cashew cultivars, farmers' cashew management practices, and how these factors drive deforestation in this landscape at the state and farm level. We recommend further research with equitable stakeholder participation in cashew farming systems to devise sound planning for forest conservation and sustainability standards for the cashew industry. https://doi.org/10.1371/journal.pone.0269092
Assessing the sustainability index of part-time and full-time hazelnut farms in Giresun and Ordu Province, Turkey
The study's primary purposes were to assess the sustainability of hazelnut farms and explore the effects of part-time and full-time farming types on sustainability in hazelnut production in the Giresun and Ordu Province of Turkey. One hundred fifty-two hazelnut farms were selected using the stratified sampling method, and data were collected by using face-to-face questionnaires. Several steps were taken, including using factor analysis after standardizing the variables to determine their weights to calculate the composite hazelnut farms' sustainability index. The research findings showed that overall hazelnut sustainability scores of farms varied from 0.28 to 0.59, and the average score was 0.44 at sampled farms. The composite hazelnut sustainability index was at an unsatisfactory level. The social and economic sustainability index values of farms were equal, and they were higher than the environmental index value. The values were 0.50 and 0.30, respectively. The economic sustainability index score of full-time farms was higher than that of part-time farms, and part-time farms had higher environmental sustainability index scores than that of full-time farms. Social sustainability scores were not different in terms of farm type. It was recommended that when designing and regulating support policies, policy-makers should differentiate part-time and full-time farming. Training and extension programs must be planned to increase the level of knowledge of every willing farmer. To increase sustainability, specific policies are developed according to the farming type. https://doi.org/10.1007/s11356-022-20966-9
Pecan agroforestry systems improve soil quality by stimulating enzyme activity.
Background: Forest and plantation intercropping are efficient agroforestry systems that optimize land use and promote agroforestry around the world. However, diverse agroforestry systems on the same upper-plantation differently affect the physical and chemical properties of the soil. Methods: The treatments for this study included a single cultivation (CK) pecan control and three agroforestry systems (pecan + Paeonia suffruticosa + Hemerocallis citrina, pecan + Paeonia suffruticosa, and pecan + Paeonia lactiflora). Soil samples were categorized according to the sampling depth (0-20 cm, 20-40 cm, 40-60 cm). Results: The results demonstrated that the bulk density (BD) of soil under the pecan agroforestry system (PPH and PPL) was reduced by 16.13% and 7.10%, respectively, and the soil moisture content (MC) and total soil porosity (TPO) increased. Improvements in the physical properties of the soil under the PPS agroforestry system were not obvious when compared with the pecan monoculture. The soil total phosphorus (TP), total nitrogen (TN), available potassium (AK), and total carbon (TC) increased significantly, while the soil urease (S-UE), alkaline phosphatase (S-AKP), and 1,4-β-N-acetylglucosamines (S-NAG) enzyme activity also increased significantly, following agroforestry. Overall, the pecan agroforestry system significantly improved the physical properties of the pecan plantation soil, enriched the soil nutrients, and increased the activity of soil enzymes related to TC, TN, and TP cycles. https://doi.org/10.7717/peerj.12663
Presence of activated carbon particles from waste walnut shell as a biosorbent in monoethanolamine (MEA) solution to enhance carbon dioxide absorption
Greenhouse effects are a natural phenomenon that plays a high role in shaping the climate system. In this research, MEA solution was used for CO2 capture in presence of activated carbon particles from waste walnut shells as a biosorbent. The process parameters including temperature, pressure, MEA concentration, and activated carbon were used in the central composite design (CCD) model. The absorption experiments were carried out in a laboratory setup at operational conditions including temperature in range of 20-60 °C, pressure in range of 3.5-9.5 bar, MEA concentration in range of 2.5-8.5 wt%, and active carbon amount in range of 0.3-0.9 g/L. The process responses including CO2 loading, the amounts of CO2 absorption, and absorption percentage were obtained in the range of 0.444-0.720 molCO2/molMEA, 0.294-0.687 mol/L, and 19.32-52.25%, respectively. The optimal value of CO2 loading was obtained at temperature of 30 °C, pressure of 5.19 bar, activated carbon of 0.75 g, and MEA concentration of 7.00 wt%. The optimum values of responses were obtained 0.531, 0.609 mol/L and 50.04% for maximum loading, absorption amount, and absorption percentage, respectively. From the results, carbon dioxide loading in MEA solution increases in presence of activated carbon particles. https://doi.org/10.1016/j.heliyon.2021.e08689
Dryland irrigation increases accumulation rates of pedogenic carbonate and releases soil abiotic CO2
Agricultural fields in drylands are challenged globally by limited freshwater resources for irrigation and also by elevated soil salinity and sodicity. It is well known that pedogenic carbonate is less soluble than evaporate salts and commonly forms in natural drylands. However, few studies have evaluated how irrigation loads dissolved calcium and bicarbonate to agricultural fields, accelerating formation rates of secondary calcite and simultaneously releasing abiotic CO2 to the atmosphere. This study reports one of the first geochemical and isotopic studies of such "anthropogenic" pedogenic carbonates and CO2 from irrigated drylands of southwestern United States. A pecan orchard and an alfalfa field, where flood-irrigation using the Rio Grande river is a common practice, were compared to a nearby natural dryland site. Strontium and carbon isotope ratios show that bulk pedogenic carbonates in irrigated soils at the pecan orchard primarily formed due to flood-irrigation, and that approximately 20-50% of soil CO2 in these irrigated soils is calcite-derived abiotic CO2 instead of soil-respired or atmospheric origins. Multiple variables that control the salt buildup in this region are identified and impact the crop production and soil sustainability regionally and globally. Irrigation intensity and water chemistry (irrigation water quantity and quality) dictate salt loading, and soil texture governs water infiltration and salt leaching. In the study area, agricultural soils have accumulated up to 10 wt% of calcite after just about 100 years of cultivation. These rates will likely increase in the future due to the combined effects of climate variability (reduced rainfall and more intense evaporation), use of more brackish groundwater for irrigation, and reduced porosity in soils. The enhanced accumulation rates of pedogenic carbonate are accompanied by release of large amounts of abiotic CO2 from irrigated drylands to atmosphere. Extensive field studies and modelling approaches are needed to further quantify these effluxes at local, regional and global scales. https://doi.org/10.1038/s41598-021-04226-3
Multipurpose plant species and circular economy: Corylus avellana L. as a study case.
Corylus avellana L. is one of the most cultivated species in the world. Mainly utilized with the purpose of obtaining food material, hazel trees cannot guarantee constant kernels productions given the threats related to pathogens and to adverse conditions, especially in a globalisation and global changes scenarios. This matter led us to consider the opportunity of using hazel tree in all its parts and for several purposes, due to its multifunctional characteristics. As a pioneer species, it is a precious plant useful for forest restoration purposes and for forest successions/wildlife facilitation. Its roots enter into symbiosis with truffles making this species exploitable for hazelnuts and truffles production. The precious elements contained in what is considered "waste" deriving from hazel crops (i.e., leaves, skins, shells, husks and pruning material), could be reused and valorised in the perspective of a circular economy that is opposed to a linear one. In particular, a list of several phenolic compounds detected in hazelnut shells has been reported in literature to prevent and delay many human diseases due to their antioxidant properties and to free radical scavenging activities, with implications potentially useful even in the fight against COVID-19. All this makes hazel crop by-products interesting to be valorised as a chemical compound source for human health, even more than a biomass fuel or for bio-char applications. The multiple possible uses of the hazel tree would lead to alternative productions than the only nut productions, avoiding significant economic losses, would decrease the cost of disposal of crops residues and would increase the sustainability of agro-ecosystems by reducing, among other things, the production of wastes and of greenhouse gases deriving from the usual burning of residues which often happens directly in fields. https://doi.org/10.31083/j.fbl2701011
Acute Toxicity of Fungicide-Insecticide-Adjuvant Combinations Applied to Almonds During Bloom on Adult Honey Bees.
Beekeepers report significant honey bee deaths during and after almond bloom. These losses pose a major problem for the California almond industry because of its dependence on honey bees as pollinators. This research aimed to determine if combinations of pesticides applied during almond bloom during daylight hours were a possible explanation for these losses. In the present study, we aimed to mimic the spray application route of exposure to pesticides by using a Potter Spray Tower to treat adult honey bees with commonly encountered pesticides and pesticide combinations at multiples of the maximum recommended field application rates. Tested insecticides included Altacor® and Intrepid® and tested fungicides included Tilt®, Pristine®, Luna Sensation®, and Vangard®. Synergistic toxicity was observed when the fungicide Tilt® (a.i. propiconazole) was applied with the insecticide Altacor® (chlorantraniliprole), though neither caused significant mortality when applied individually. The study also looked at the effect of adding a spray adjuvant, Dyne-Amic®, to pesticide mixtures. Dyne-Amic® was toxic to honey bees at concentrations above the maximum recommended field application rate and toxicity was increased when combined with the fungicide Pristine® (pyraclostrobin and boscalid). Addition of Dyne-Amic® also increased toxicity of the Tilt® and Altacor® combination. These results suggest that application of Altacor® and Tilt® in combination with an adjuvant at the recommended field application rates could cause mortality in adult honey bees. These findings highlight a potential explanation for honey bee losses around almond bloom, emphasize that the safety of spray adjuvants to bees should not be assumed, and provide support for recommendations to protect bees from pesticides through application at night when bees are not foraging. https://doi.org/10.1002/etc.5297
Effects of different artificial diets on commercial honey bee colony performance, health biomarkers, and gut microbiota.
Background: Honey bee colonies managed for agricultural pollination are highly dependent on human inputs, especially for disease control and supplemental nutrition. Hives are routinely fed artificial "pollen substitute" diets to compensate for insufficient nutritional forage in the environment. The aim of this study was to investigate the effects of different artificial diets in a northern California, US commercial beekeeping operation from August through February. This time period represents an extended forage dearth when supplemental nutrition is used to stimulate late winter colony growth prior to almond pollination in the early spring. A total of 144 honey bee colonies were divided into 8 feeding groups that were replicated at three apiary sites. Feeding groups received commercial diets (Global, Ultra Bee, Bulk Soft, MegaBee, AP23, Healthy Bees), a beekeeper-formulated diet (Homebrew), or a sugar negative control. Diets were analyzed for macronutrient and amino acid content then evaluated with respect to honey bee colony population size, average bee weight, nutrition-related gene expression, gut microbiota abundance, and pathogen levels. Results: Replicated at three apiary sites, two pollen-containing diets (Global and Homebrew) produced the largest colonies and the heaviest bees per colony. Two diets (Bulk Soft and AP23) that did not contain pollen led to significantly larger colonies than a sugar negative control diet. Diet macronutrient content was not correlated with colony size or health biomarkers. The sum of dietary essential amino acid deficiencies relative to leucine content were correlated with average bee weight in November and colony size used for almond pollination in February. Nutrition-related gene expression, gut microbiota, and pathogen levels were influenced by apiary site, which overrode some diet effects. Regarding microbiota, diet had a significant impact on the abundance of Bifidobacterium and Gilliamella and trended towards effects on other prominent bee gut taxa. Conclusions: Multiple colony and individual bee measures are necessary to test diet efficacy since honey bee nutritional responses are complex to evaluate. Balancing essential amino acid content relative to leucine instead of tryptophan may improve diet protein efficiency ratios. Optimization of bee diets could improve feed sustainability and agricultural pollination efficiency by supporting larger, healthier honey bee colonies. https://doi.org/10.1186/s12917-022-03151-5
Assessing climate risk to support urban forests in a changing climate.
Globally, cities are planning for resilience through urban greening initiatives as governments understand the importance of urban forests in improving quality of life and mitigating climate change. However, the persistence of urban forests and the ecosystem benefits they provide are threatened by climate change, and systematic assessments of causes of tree dieback and mortality in urban environments are rare. Long-term monitoring studies and adaptive management are needed to identify and prevent climate change-driven failures and mortality. Research and monitoring when coupled with systematic forecasting will enable governments to incorporate climate change resilience into urban forestry planning. Future scenarios in which urban forests are resilient or in decline will depend on the management and planning actions we make today. https://doi.org/10.1002/ppp3.10240