Organic Crop Research Articles

Greenhouse gas emissions, carbon stocks and wheat productivity following biochar, compost and vermicompost amendments: comparison of non-saline and salt-affected soils

Understanding the impact of greenhouse gas (GHG) emissions and carbon stock is crucial for effective climate change assessment and agroecosystem management. However, little is known about the effects of organic amendments on GHG emissions and dynamic changes in carbon stocks in salt-affected soils. We conducted a pot experiment with four treatments including control (only fertilizers addition), biochar, vermicompost, and compost on non-saline and salt-affected soils, with the application on a carbon equivalent basis under wheat crop production. Our results revealed that the addition of vermicompost significantly increased soil organic carbon content by 18% in non-saline soil and 52% in salt-affected soil compared to the control leading to improvements in crop productivity i.e., plant dry biomass production by 57% in non-saline soil with vermicompost, while 56% with the same treatment in salt-affected soil. The grain yield was also noted 44 and 50% more with vermicompost treatment in non-saline and salt-affected soil, respectively. Chlorophyll contents were observed maximum with vermicompost in non-saline (24%), and salt-affected soils (22%) with same treatments. Photosynthetic rate (47% and 53%), stomatal conductance (60% and 12%), and relative water contents (38% and 27%) were also noted maximum with the same treatment in non-saline and salt-affected soils, respectively. However, the highest carbon dioxide emissions were observed in vermicompost- and compost-treated soils, leading to an increase in emissions of 46% in non-saline soil and 74% in salt-affected soil compared to the control. The compost treatment resulted in the highest nitrous oxide emissions, with an increase of 57% in non-saline soil and 62% in salt-affected soil compared to the control. In saline and non-saline soils treated with vermicompost, the global warming potential was recorded as 267% and 81% more than the control, respectively. All treatments, except biochar in non-saline soil, showed increased net GHG emissions due to organic amendment application. However, biochar reduced net emissions by 12% in non-saline soil. The application of organic amendments increased soil organic carbon content and crop yield in both non-saline and salt-affected soils. In conclusion, biochar is most effective among all tested organic amendments at increasing soil organic carbon content in both non-saline and salt-affected soils, which could have potential benefits for soil health and crop production.

Sustainable basmati rice yield and quality enhancement through long-term organic nutrient management in the Indo-Gangetic Plains

Context or problemThe extensive use of chemical fertilizers and pesticides in modern agriculture, particularly since the green revolution, has led to profound consequences for agricultural ecosystems. This approach, while initially boosting yields, has disrupted soil health, biodiversity, and environmental balance. Moreover, it contributes silently to global climate change by releasing greenhouse gases. These challenges underscore the urgent need for a shift towards sustainable agricultural practices to safeguard soil health, biodiversity, and human nutrition while mitigating the impacts of climate change. Objective or research questionThe primary objective of this study is to assess the impact of the long-term (seventeen years) application of organic nutrient management on the physicochemical properties of basmati rice soil and its nutritional quality. The study aims to understand the effectiveness of different organic nutrient management practices in mitigating the negative consequences associated with conventional agricultural practices. MethodsThe experiment used a strip-plot design with three replications, assigning two cropping systems (basmati rice-wheat-green gram and basmati rice-wheat-sesbania) to vertical strips. Seven nutrient management practices, including control, farmyard manure (FYM), vermicompost, farmyard manure + crop residues, vermicompost + crop residues, farmyard manure + crop residues + biofertilizers, and vermicompost + crop residues + biofertilizers [nitrogen-fixing Azospirillum, phosphorus-solubilizing bacteria (PSB), potassium-solubilizing bacteria (KSB), and a cellulolytic culture (Aspergillus awamori, Trichoderma viride, Phanerochaete chrysosporium, and Aspergillus wululens)] were applied to the horizontal strips. ResultsThe findings show that the cropping system with sesbania green manure significantly improved soil physicochemical attributes, nutritional content, and basmati rice yield compared to the green gram-based system. Continued application of organic manures, crop residues, and biofertilizers notably enhanced soil fertility, grain quality, and basmati rice productivity. The combined use of vermicompost, wheat residue, biofertilizers, and sesbania green manure treatment increased organic carbon content by 78.7% over the control, and soil available nitrogen, phosphorus, and potassium by 38.3–54.9%, 57.6–143.8%, and 27.9–64.1%, respectively. Additionally, it augmented diethylenetriamine pentaacetic acid extractable iron, zinc, manganese, and copper content by up to 44.2%, 28.5%, 57.9%, and 71.0%, respectively. Co-application of the above organic sources also significantly enhanced grain and straw yields by 74.5–80.1% and 46.1–50.0%, respectively, compared to the control. ConclusionsEnhancing Basmati rice yield and quality in the Indo-Gangetic Plains can be sustainably achieved through sesbania green manuring and organic practices. Positive correlations with key soil parameters emphasize the significance of organic farming for long-term sustainability. Implications and significanceThe study suggests that adopting organic practices, including sesbania green manuring and combining organic inputs, can alleviate the adverse effects of conventional farming on soil health, biodiversity, and climate change. This aligns with the broader goal of establishing sustainable production and consumption in basmati rice-based cropping systems.

Esterco bovino e substâncias húmicas estimulam a morfofisiologia e a nutrição em pimentão

ABSTRACT Species of the genus Capsicum, especially peppers, are economically important and widely consumed worldwide. The application of animal waste as organic fertilizer is a simple and cost-effective technique for applying nutrients to the soil. Combining cattle manure with humic substances can stimulate plant metabolism, resulting in increased nutrient absorption and assimilation. Therefore, the objective in this study was to evaluate doses of cattle manure combined with humic substances for stimulating plant metabolism and morphophysiological and nutritional processes in pepper plants. A randomized block design with four replicates was used, in a 4×3 factorial arrangement consisting of four cattle manure doses (8, 18, 28, and 38 Mg ha-1) and three humic substance doses (0, 8, and 12 kg ha-1). Humic substances (12 kg ha-1) enhanced gas exchange, increasing net photosynthesis (34.2%), stomatal conductance (12.7%), instantaneous water use efficiency (15.87%), instantaneous carboxylation efficiency (37.37%), and absorbed energy conversion efficiency (23.53%). Cattle manure adequately met the crop’s nutritional requirements, while humic substances increased the number and thickness of plant root hairs. The most effective combination to increase photosynthetic activity in pepper plants was 38 Mg ha-1 of cattle manure combined with 8 kg ha-1 of humic substances. Humic substances stimulated positive morphophysiological responses in organic pepper crops, which resulted in increased production.

Technological quality of common bean landraces from organic cropping system

Beans are an important constituent of the Brazilian diet, and the search for cultivars with good culinary characteristics and adapted to the place of cultivation is necessary. It is known that there is a wide genetic diversity for common bean landrace cultivars. Still, little is known experimentally about the behavior of these cultivars when produced under organic cultivation. This work aimed to evaluate the technological quality of common bean landraces produced under organic cropping system. Twenty-six cultivars were used, four commercial and twenty-two landraces, originating from the Active Bean Germplasm Bank (BAF) of Santa Catarina State University – Agroveterinary Sciences Center (UDESC/CAV), produced in organic and conventional cultivation, in two crops. Cooking time and resistance, percentage of water absorption and broken grains and total soluble solids were evaluated. The shortest cooking time for the grains cultivated in the organic system (18 to 22 minutes) was obtained. The cultivars that had a percentage of unbroken grains between 60 and 80% showed a higher content of total soluble solids in the broth. Based on the genetic diversity for technological quality in organic cropping system, the use of cultivars, BAFs: 60, 23, 81, 13, 68, 55, 75 and 36 are indicated to integrate genetic improvement programs or to be used by small farmers for bean production.

Spillover effects of organic agriculture on pesticide use on nearby fields.

The environmental impacts of organic agriculture are only partially understood and whether such practices have spillover effects on pests or pest control activity in nearby fields remains unknown. Using about 14,000 field observations per year from 2013 to 2019 in Kern County, California, we postulate that organic crop producers benefit from surrounding organic fields decreasing overall pesticide use and, specifically, pesticides targeting insect pests. Conventional fields, by contrast, tend to increase pesticide use as the area of surrounding organic production increases. Our simulation suggests that spatially clustering organic cropland can entirely mitigate spillover effects that lead to an increase in net pesticide use.

The Enzyme Activity of Dual-Domain β-Propeller Alkaline Phytase as a Potential Factor in Improving Soil Phosphorus Fertility and Triticum aestivum Growth

The widespread use of non-renewable phosphate fertilizers in agriculture poses a significant pollution threat to soil, necessitating the exploration of sustainable alternatives for phosphate fertility. Releasing phytate phosphorus through microbial phytases presents an eco-friendly solution for sustainable phosphate fertility in agriculture. This study directly inoculated dual-domain β-propeller alkaline phytase (phyHT) derived from Bacillus sp. HJB17 into the soil. The study analyzed the impact of inoculated phyHT on the physicochemical properties of the soil, assessed the variations in enzyme activity of phyHT within the soil, and examined the effects of the treated soil on wheat growth. Additionally, the study explored the enhancement of the available phosphorus in the soil through the inoculation of phyHT in both crop residues and organic fertilizer. PhyHT exhibited the highest catalytic activity at 37 °C and pH 8.0. After soil adsorption, phyHT maintained stable enzymatic activity. PhyHT markedly boosted the available phosphorus in the soil while reducing the soil phytate content by about 20%, increasing the phosphorus levels and enhancing soil fertility. PhyHT effectively degraded phytates in an organic fertilizer and crop residues, increasing the available phosphorus. PhyHT supplementation enhanced growth, biomass, and phosphorus content in both the shoot and root weights of Triticum aestivum. This study establishes phyHT as a viable and eco-friendly method to enhance phosphorus fertility in soil. The direct application of microbial phytases can serve as a sustainable source of phosphate fertility in soil.

Enhancing Sustainable Agriculture in China: A Meta-Analysis of the Impact of Straw and Manure on Crop Yield and Soil Fertility

As the main organic materials, straw and manure play a critical role in soil organic carbon (SOC) sequestration and crop yield in China. This meta-analysis evaluated the impact of straw and manure amendments, both individually and combined, on crop yield, SOC, and soil nutrients in China by collecting 173 studies. The findings of this study revealed that straw return and manure application increased crop yields by 14.4% and 70.4%, respectively, overall. Combined straw and manure application gained a better improvement effect than straw alone but was less effective than manure alone. Regarding the straw return results, rice straw and a 3000–6000 kg ha−1 returning quantity improved crop yield, SOC, available phosphorus (AP), available potassium (AK), and total nitrogen (TN) the most; regarding the straw return form, straw incorporated into soil and biochar increased crop yield and SOC more, respectively; and <5 years and ≥5 years of straw return treatment increased crop yield and TN more, respectively. Regarding manure application, pig and chicken manure increased crop yield and TN more, respectively; a 50–80% substitution ratio and 10–20 years of duration were best for improving crop yield, SOC, AP, AK, and TN. This study highlights the importance of optimal organic amendment through straw or manure applications to achieve a win–win between crop yield and soil fertility under the requirement of sustainable agriculture.

Fertility of drained sod-podzolic soil in organic crop rotation

Fertility of drained sod-podzolic soil in organic crop rotation

Row unit down force and coulter effects vary by environmental conditions in organic no‐till soybeans

AbstractConcerns over tillage intensity and soil erosion in organic cropping systems have prompted the development of reduced tillage organic systems that use cover crops rather than soil disturbance as the primary weed control tool. However, planting into high residue cover crop mulches may inhibit crop establishment due to poor seed placement. Adaptation of agricultural equipment to high residue planting conditions could reduce variability in crop stands, thereby improving grain yield. Field trials at the University of Wisconsin Arlington Agricultural Research Station, Marshfield Agricultural Research Station, and three on‐farm locations representing seven site‐years of data from 2019 to 2020 comprised a 2 × 2 × 2 × 2 factorial experiment comparing (1) a low (457,135 seeds ha−1) versus high (555,986 seeds ha−1) soybean [Glycine max (L.) Merr.] seeding rate, (2) a 13 fluted‐wavy coulter versus no coulter attachment, (3) low (667 N) versus high (1334 N) row unit down force, and (4) spiked versus rubber closing wheels on soybean stand establishment and grain yield in an organic cover crop–based reduced tillage system. Combined across site‐years, high row unit down force and coulters increased soybean stand establishment by 2.3% and 2.4%, respectively; however, the magnitude and direction of effects varied within each site‐year. Winter rye (Secale cereale L.) biomass accumulation negatively correlated to soybean stand establishment and demonstrated trends toward increasing soybean yield. Significant correlations between soybean stand establishment and yield were noted under high rye biomass conditions, indicating potential improvements to soybean yields by increasing plant stands.

Restoration of soil fertility and improvement of phytosanitary condition of soil in short rotation of crops in Polissia of Ukraine

With the intensification of agricultural land use and changes in natural conditions, soil quality in Ukraine is deteriorating, with a decrease in humus content, the average annual loss of which is about 0.6 t/ha. Therefore, its reproduction is now becoming increasingly important through the use of organic raw materials and the introduction of legumes into the crop rotation, which leads to a partial replacement of nitrogen from mineral fertilisers with biological nitrogen. The purpose of this study was to find ways to provide the topsoil with organic residues, develop soil microflora, and improve the activity of nitrogen-fixing bacteria in a short grain legume crop rotation. The study was conducted in 2019-2023 using the following methods: visual – to determine the stages of organogenesis; field – to determine the interaction of abiotic factors; physiological – to determine the symbiotic fixation of atmospheric nitrogen. It was found that due to mineralisation of organic residues of legume crop rotation, the amount of macro- and microelements in the soil layers 0-10 cm, 10-20 cm, and 20-30 cm increased by 45.1-46.9-43.1 mg/kg, respectively. It was found that saturation of short crop rotation by 50% with legumes, straw residues, and green manure contributed to the reduction of pathogenic microorganisms and the growth of suppressive ones. It was found that in a short rotation of crops, 10.3 t/ha of organic matter in the form of stubble and root residues, straw and green manure enters the soil, which contributed to the cultivation of environmentally friendly agricultural products with the restoration of soil fertility. The biological activity of the soil during the growing season in the layer of 10-20 cm reached 47.4%, and the content of alkaline hydrolysed nitrogen in the rhizosphere of the root system increased by 43.9 mg/kg. The value of the study lies in the fact that the introduction of short organic crop rotations in farms of various forms of ownership is an innovative approach to providing light grey soils with organic raw materials, restoring and maintaining their fertility, improving their phytosanitary condition, promoting biodiversity, achieving environmental sustainability and high yields

Efficiency of spring wheat cultivation in short-rotation organic crop rotation under left-bank Forest-Steppe conditions

Efficiency of spring wheat cultivation in short-rotation organic crop rotation under left-bank Forest-Steppe conditions

Soybean cultivation in short rotation organic crop rotation under different fertilisation systems

Soybean cultivation in short rotation organic crop rotation under different fertilisation systems

Sorghum and cowpea intercropping response to woody residue amendments in Sahelian agro-ecosystems of Burkina Faso

In West African agro-ecosystems, soils are inherently low in soil organic carbon decreasing the capacity of soils to sustain crop productivity. Woody Residues instead of being burnt or exported out of the cropping systems, can be managed to optimize soil organic carbon build-up, nutrient cycling and crop productivity. The aim of this study was to determine the effect of woody residue amendments from Piliostigma reticulatum (D.C.) Hochst associated with sorghum-cowpea intercropping on the soil residual property and crop productivity. The investigation was carried out in two experimental sites in the Sudano-Sahelian (Gampela and Kulungu) area of Burkina Faso (West Africa). The experimental design was organized into four replicates consisting of two treatments of woody residue amendments: amended (WR+) and unamended (WR-) soils. The results for both sites showed an overall significant increase in numbers (+ 35%) and biomass (+ 64%) of cowpea nodules. The root and aerial biomasses at the flowering stage of cowpeas were significantly improved in amended soils (WR+) by 26% and 44%, respectively compared to unamended soils (WR-). In addition, the WR+ treatment increase significantly cowpea and sorghum yields by 41% and 25%, respectively, as well as water use efficiency (+ 40% and + 26%, respectively) compared to the WR- treatment. Moreover, our results exhibited a strong correlation (r = 0,95) between cowpea nodular biomass and sorghum grain yields, reflecting more contribution of cowpea ecosystem services (facilitation and complementarity) for associated sorghum productivity. However, despite favorable soil conditions (soil water and organic carbon content) that occurred by WR input, it was not sufficient to improve soil residual total nitrogen and available phosphorus. The woody residue management associated with cereal-legume intercropping is a promising option to sustain crop productivity in Sahelian agro-ecosystems.

Processing of Legume Green Manures Slowdowns C Release, Reduces N Losses and Increases N Synchronisation Index for Two Years

The number of livestock farms decreased by 40% in Europe over the last 10-year period. Stockless organic cropping systems started to dominate in many intensive agricultural regions in Europe. Developing the sustainable management of an organic stockless agroecosystem is related to guaranteeing self-sufficiency in nitrogen (N) supply, maintaining high grain yields, and promoting carbon (C) sequestration in the soil. The aim of this study was to investigate if the processed legume green manures can be an alternative to granulated cattle manure and direct ploughing of legume biomass in order to develop the sustainability of the stockless organic cropping system. The decomposition rate and C and N release were observed for green manures made of fermented red clover and composted red clover with wheat straw. Fresh red clover biomass and granulated cattle manure were used for the comparison. Results of the 3-year field experiment showed that technologically processed legume biomass had a positive effect on the productivity of crops at least two years in rotation. Fermented red clover and red clover compost increased N use efficiency by 15% and biomass output efficiency by 16% compared with fresh red clover biomass. Processed legume green manures significantly increased the synchronisation index between crop N demand and N supply. In autumn, incorporated fresh red clover biomass lost 65.6% of its initial C and 37.6 kg ha−1 (50.1%) of its initial N under decomposition in the first non-growing season. It also increased mineral N losses deeper into the subsoil by 52.7%. Meanwhile, fermented red clover and red clover compost released 43% of its N during the first crop growing season, sustained at least one year slower C release to the soil, promoted ecosystem productivity, prevented mineral N losses to subsoil and gained high N synchrony indexes. The best N synchrony was achieved using fermented red clover, with a higher decomposition rate positively significantly correlated (r = 0.47–0.78, p < 0.05) with grain yield, total biomass, protein content and total N accumulated in the plant of spring wheat and spring barley.

Policy measures effectively reduce soil nitrous oxide emissions with minor trade‐offs in crop yield

AbstractNitrous oxide (N2O) emissions are closely linked to agricultural fertilisation. European and national policy incentives have been set to reduce greenhouse gas (GHG) emissions; however, only a few evaluations have been conducted. Avoiding such emissions is an important climate change mitigation measure, but it is still uncertain which management measures over a long‐term, best out‐balance crop yield and GHG balances in agricultural systems. We here used the process‐based LandscapeDNDC model to simulate N2O emissions and trade‐offs in yield and soil nitrogen budget for four alternative arable cropping systems in three Austrian agricultural production zones belonging to different climatic regions. We evaluated statistical data on crop rotations and management practices, predominant soil types, and 10‐year daily weather conditions for four cropping systems: (1) conventional farming receiving the maximum allowed nitrogen fertilisation rate (Nmax), (2) conventional farming receiving 15% less fertiliser, (3) conventional farming receiving 25% less fertiliser, and (4) organic farming. Our results showed that soil N2O emissions could be best reduced in wet, high‐yield regions. Reducing nitrogen fertilisation by 15% and 25% mitigated N2O emissions by, on average, 22% and 39%, respectively, while the yield was reduced by 5% and 9%, respectively. In comparison, the same crops grown in the organic cropping system released 60% less N2O, but yield declined on average by 23%. Corn, winter barley, and vegetables showed the highest N2O reduction potential under reduced fertiliser input in conventional farming. In addition to N2O emissions, reduced fertilisation substantially decreased other nitrogen losses into the water and atmosphere. Generally, the soils under all cropping systems maintained a positive mean nitrogen budget. Our results suggest a significant emission reduction potential in certain production zones which, however, were accompanied by yield reductions. Knowledge of the emission patterns from cropping systems under different environmental conditions is essential to set the appropriate measures. In addition, region‐specific measures to reduce soil N2O emissions have to be in line with farmers' interests in order to facilitate the successful implementation of targeted nitrogen management.

Evidencing the importance of the functional unit in comparative life cycle assessment of organic berry crops.

LCA methodology provides the best framework to evaluate environmental impacts in agriculture systems. However, the interpretation of LCA results, in particular when the objective was to compare different production systems, could be affected by the selection of the functional unit (FU). That is why an accurate definition of the FU, in agreement with the function considered for the systems analysed, is essential. In this work, the organic production at small scale of blueberry, raspberry, blackberry and cape gooseberry in North Spain has been analysed following LCA methodology. Although a different distribution of environmental loads was obtained for each crop, in all cases, the main contributions to most of the considered environmental categories were electric and fertiliser consumptions. The different production systems have been compared on the basis of the environmental impacts associated considering different FUs, i.e. based on fruit mass, cultivated area, farm-gate price and nutritional quality of fruits. Carbon footprints (CF) have been also calculated. It was observed that the order of the crops with respect to their environmental performances was the same for the blueberry and raspberry crops (with the lowest and the highest CF, respectively), independently of the selected FU, whereas the order of the blackberry and cape gooseberry crops was interchanged, depending on the FU used. This work supports the need of being aware of the final objective of the orchards when choosing the FU (i.e. producing fruits, cultivating an area, economic benefits or nourishing people), so that valid conclusions can be achieved from the environmental comparison, even for different agricultural products.

Non-chemical management of weeds through bioherbicides: current status, market, development, constraints and future prospects

A weed, a kind of pest, is a plant growing where it is not desired, or a plant out of its place. Weeds are a major threat to biodiversity and agricultural productivity. The annual losses caused by weeds has been estimated to over US$26 billion in the USA, AU$ 3.3 billion in Australia and US$ 11 billion in India exclusively in 10 major crops. The rising awareness about the potential health risk with chemical residues among individuals and farmers, emphasis is on growing organic crops to keep us healthy and a long life. In addition, the constant use of herbicides in agriculture system also paves the way for the emergence of resistance of weed variety. Bioherbicides, an eco-friendly alternative to non-chemical management of weeds, are defined as the formulations based on indigenous living host-specific microorganisms and ancillary components applied in an inundative manner similar to chemical herbicides. The term microbial herbicide preferably be used for microbial-based formulations. These are derived from fungi, bacteria and viruses. The bioherbicides market is rapidly growing and expected to witness market growth at a rate of 15% and is expected to reach US$1.84 by 2029. In spite of all efforts, acceptance of bioherbicides by the users is low due to a wide range of constraints (e.g., environmental, technological, host-specificity, regulatory, funding and human-related). Environmental conditions playing a significant role on the microbial germination, penetration, infection and biocontrol efficacy of the target host. Twenty-six microbe-based herbicides have been developed globally. At present, 13 bioherbicides are available in the market namely DeVineTM, CollegoTM (LockdownR), BioMalR, BioChonTM, MycoTechTM, Chontrol™ (EcoClearTM), SmolderR, SarritorTM, SolvinixR, Gibbartrianth, BiophomaTM and Di-Bak ParkinsoniaR. For successful deployment of bioherbicides into agriculture, horticulture and forestry, in addition to boosting their market, scientists need to develop consumer-friendly bioherbicides with a long-shelf life, non-effected by environmental conditions, ability to control varied weeds in a crop, and with a biocontrol efficacy better than or at par with the synthetic herbicides. Objective of this review is to discuss biocontrol strategies for controlling weeds, phases of bioherbicide development, market, current global status, development of currently available bioherbicides, constraints/limitations in their production & demand and future prospects for their adoption in weed management system.

Economic Injury Levels and Economic Thresholds for Leucoptera coffeella as a Function of Insecticide Application Technology in Organic and Conventional Coffee (Coffea arabica), Farms.

Leucoptera coffeella (Lepidoptera: Lyonetiidae) is one of the main pests in coffee crops. The economic injury level (EIL) is the lowest density of the pest at which economic damages match the costs of control measures. The economic threshold (ET) is the density of the pest at which control measures must be taken so that this population does not reach the EIL. These are the main indices used for pest control decision-making. Control of L. coffeella is carried out by manual, tractor, airplane or drone applications. This work aimed to determine EILs and ETs for L. coffeella as a function of insecticide application technology in conventional and organic Coffea arabica crops. Data were collected over five years in commercial C. arabica crops on seven 100 ha central pivots. The cost of control in organic crops was 16.98% higher than conventional. The decreasing order of control cost was manual > drone > airplane > tractor application. Coffee plants were tolerant to low densities (up to 15% mined leaves) of the pest that caused losses of up to 6.56%. At high pest densities (54.20% mined leaves), losses were high (85.62%). In organic and conventional crops and with the use of different insecticide application technologies, EIL and ET were similar. The EIL and ET were 14% and 11% of mined leaves, respectively. Therefore, these indices can be incorporated in integrated pest management programs in C. arabica crops. The indices determined as a function of insecticide application technology in organic and conventional coffee are important as they serve producers with different technological levels. Additionally, EILs and ETs can contribute to more sustainable production, as control methods will only be employed when the pest density reaches these indices.

Seedcorn maggot response to planting date, cover crops, and tillage in organic cropping systems.

Seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is an economically important early-season pest of corn and soybean in the United States. Adult seedcorn maggot is attracted to decomposing plant residues for oviposition, creating potential management issues where growers typically use tillage to incorporate fertility amendments and to create a seedbed. The use of growing degree-day models to time planting dates is an important tool for effectively managing this pest, but their use has not been examined in organic crop production. Here, we report the results of experiments to determine the effects of cover crops, tillage, and relative planting date on seedcorn maggot in corn and soybean in 2 experiments: The first during the transition to organic from conventional management and the second during the 3 yr following organic certification in central Pennsylvania, United States. Overall, delaying the planting date by 1-2 wk reduced fly emergence in corn, but not in soybean in both experiments. Seedcorn maggot emergence was also consistently greater in corn than in soybean, with 6 times more flies in corn than in soy. About 15 times more seedcorn maggot flies emerged from corn in treatments in which cover crops were managed with tillage compared to treatments in which cover crops were terminated with a roller-crimper followed by no-till planting of corn. Fly emergence was negatively related to the proportion of legumes in the cover crop mixture preceding corn. These results can help inform soil, cover crop, and crop decisions for organic growers in the Mid-Atlantic United States.

Effect of Genotype, Environment, and Their Interaction on the Antioxidant Properties of Durum Wheat: Impact of Nitrogen Fertilization and Sowing Time

In this study, the influence of genotype (G), environment (E), and their interaction (G × E) on the content of total free phenolic compounds (TPC) and the antioxidant capacity (AC) was investigated, using sixteen durum wheat genotypes cultivated under seven crop management systems in Mediterranean environments. Possible correlations between TPC and AC with protein content (PC) and vitreous kernel percentage (VKP) were examined. Gs that exhibited stability across diverse conditions were studied through a comprehensive exploration of G × E interaction using a GGE biplot, Pi, and 𝘒R. The results indicated significant impacts of E, G, and G × E on both TPC and AC. Across E, the mean values of G for TPC, ABTS (2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl), and FRAP (ferric reducing antioxidant power) values were 48.8 mg Trolox equivalents (TE)/100 g, 121.3 mg TE/100 g, 23.0 mg TE/100 g, and 88.4 mg TE/100 g, respectively. E, subjected to splitting top-dressing N fertilization, consistently showed low values, while the late-sowing ones possessed high values. Organic crop management maintained a stable position in the middle across all measurements. The predominant influence was attributed to G × E, as indicated by the order G × E > E > G for ABTS, DPPH, and FRAP, while for TPC, it was E > G × E > G. For TPC, the superior Gs included G5, G7 and G10, for ABTS included G3, G5 and G7, and for protein included G1, G9, and G16. G7 and G5 had a high presence of frequency, with G7 being the closest genotype to the ideal for both TPC and ABTS. These results suggest that the sowing time, nitrogen fertilization, and application method significantly impact the various antioxidant properties of durum wheat. This study holds significant importance as it represents one of the few comprehensive explorations of the impact of various Es, Gs, and their interactions on the TPC and AC in durum wheat, with a special emphasis on crop management and superior Gs possessing stable and high TPC and AC among them, explored by GGE biplot, Pi and 𝘒R. Further experimentation, considering the effect of the cultivation year, is necessary, to establish more robust and stable conclusions.