Stable Crop Production Research Articles

Влияние приемов орошения на структуру почвы и продуктивность посевов яровой пшеницы в сухостепном Поволжье

Irrigation plays a key role in preserving land fertility and ensuring the growth of crop yields in the arid conditions of the dry-steppe zone of the Volga region. This factor primarily limits the volume and stability of crop production. The article presents the results of studies on the study of various irrigation techniques - watering along the strips and irrigation by sprinkling. An analysis was carried out on the effect of the applied irrigation methods on the soil structure and productivity of spring wheat crops. It was found that irrigation methods had different effects on the factors of changing the water-physical properties of the soil and the spring wheat crop. The most effective in terms of productivity of spring wheat grain - a yield of 1.74 t/ha was detected during irrigation with sprinkling using wide-grip sprinklers. Irrigation in strips is less expensive, but the productivity of spring wheat is less with this type of irrigation - 1.16 t/ha. When watering along the strips immediately after the first watering, the overall duty cycle decreases. When watering by sprinkling, water-resistant units pass into the category of sprayed only by the end of the vegetation of spring wheat. Thus, strip watering had the most negative impact on the structure of dark chestnut soil under spring wheat crops. With this version of irrigation, erosion processes begin to develop to a greater extent.

Environmental factors influence the responsiveness of potato tuber yield to growing season precipitation

Understanding how environmental factors influence the responsiveness of crop yield to growing season precipitation (GSP) can reduce the risk of yield fluctuations, ensuring stable crop production. This study involved the cultivation of rainfed potatoes at three locations within the climatic transition zone of Northwest China. We employed stepwise linear regression and machine learning techniques to pinpoint the key environmental factors influencing potato tuber yield and the yield-precipitation relationship. The slope of the water-limited yield potential relationship for potatoes was determined to be 172.1 ​kg ​ha−1 ​mm−1, with an intercept at 121.2 ​mm. The potato tuber yield exhibited an upward trend with increasing GSP but declined once the precipitation exceeded 400 ​mm. However, GSP alone explained up to 30% of the variability in potato tuber yield. Factors such as soil moisture at planting, maximum temperatures during the tuber stolon initiation and bulking stages, diurnal temperature fluctuations at maturity, and excessive precipitation events during the growing season significantly influenced potato tuber yield, and consequently, the relationship between yield and GSP. Conversely, climatic factors accounted for more than 63% of the variation in potato tuber yield, with the multiple linear regression model yielding the best results. This was especially evident when the yield-precipitation relationship was categorized into two groups based on the amount and distribution of GSP, maximum temperature, and radiation levels. This analysis suggested that preventing unnecessary water evaporation when precipitation is low, improving drainage when precipitation is high, and planting potato on an optimal date can advance potato production.

Novel yeast-based biosensor for environmental monitoring of tebuconazole

Due to increasing demand for high and stable crop production, human populations are highly dependent on pesticide use for growing and storing food. Environmental monitoring of these agrochemicals is therefore of utmost importance, because of their collateral effects on ecosystem and human health. Even though most current-use analytical methods achieve low detection limits, they require procedures that are too complex and costly for routine monitoring. As such, there has been an increased interest in biosensors as alternative or complementary tools to streamline detection and quantification of environmental contaminants. In this work, we developed a biosensor for environmental monitoring of tebuconazole (TEB), a common agrochemical fungicide. For that purpose, we engineered S. cerevisiae cells with a reporter gene downstream of specific promoters that are expressed after exposure to TEB and characterized the sensitivity and specificity of this model system. After optimization, we found that this easy-to-use biosensor consistently detects TEB at concentrations above 5 μg L−1 and does not respond to realistic environmental concentrations of other tested azoles, suggesting it is specific. We propose the use of this system as a complementary tool in environmental monitoring programs, namely, in high throughput scenarios requiring screening of numerous samples.Key points• A yeast-based biosensor was developed for environmental monitoring of tebuconazole.•The biosensor offers a rapid and easy method for tebuconazole detection ≥ 5 μg L−1.•The biosensor is specific to tebuconazole at environmentally relevant concentrations.

Investigating Strategies and Practices to Enhance the Resilience of Agricultural Supply Chains in the Face of Disruptions and Uncertainties

Amidst disruptions and uncertainties, this research examines strategies to increase the resilience of agricultural supply chains. Factors such as diversification, adoption of technology, and climate-resilient agricultural practices emerge to fortify the robustness of supply chains. These events look set to become more common, and survey results point emphatically in the direction of diversifying sources and markets. Case studies offer a model for successful strategies against an uncertain future. Recognized as a resilience enabler, technology is challenged by limited access and concerns about data security and interoperability. Precision farming and geographic information system mapping are among the climate-resilient practices that help stabilize crop production. Financial limitations, which disproportionately affect small and medium-sized enterprises, prevent the implementation of resilience measures. Differences in regulatory standards across the regions create bottlenecks, and all policies have to be standardized while still being locally sensitive. The research argues for strategic interventions, such as financial support mechanisms and skills development programs to remove obstacles limiting resilience. These results have far-reaching potential to inform policymakers, industry participants, and researchers about how to build an integrated regulatory environment for innovation in technology.. KEYWORDS :Agricultural supply chains, Climate-resilient practices, Diversification, Financial constraints, Resilience, Technology adoption

Effect Analysis of Hydrogen Peroxide Using Hyperspectral Reflectance in Sorghum [Sorghum bicolor (L.) Moench] under Drought Stress.

Due to global climate change, adverse environments like drought in agricultural production are occurring frequently, increasing the need for research to ensure stable crop production. This study was conducted to determine the effect of artificial hydrogen peroxide treatment on sorghum growth to induce stress resistance in drought conditions. Hyperspectral analysis was performed to rapidly find out the effects of drought and hydrogen peroxide treatment to estimate the physiological parameters of plants related to drought and calculate the vegetation indices through PLS analysis based on hyperspectral data. The partial least squares (PLS) analysis collected chlorophyll fluorescence variables, photosynthetic parameters, leaf water potential, and hyperspectral reflectance during the stem elongation and booting stage. To find out the effect of hydrogen peroxide treatment in sorghum plants grown under 90% and 60% of field capacity in greenhouses, growth and hyperspectral reflectance were measured on the 10th and 20th days after foliar application of H2O2 at 30 mM from 1st to 5th leaf stage. The PLS analysis shows that the maximum variable fluorescence of the dark-adapted leaves was the most predictable model with R2 = 0.76, and the estimation model suitability gradually increased with O (R2 = 0.51), J (R2 = 0.73), and P (R2 = 0.75) among OJIP parameters of chlorophyll fluorescence analysis. However, the estimation suitability of predictions for moisture-related traits, vapor pressure deficit (VPD, R2 = 0.18), and leaf water potential (R2 = 0.15) using hyperspectral data was low. The hyperspectral reflectance was 10% higher at 20 days after treatment (DAT) and 3% at 20 DAT than the non-treatment in the far red and infra-red light regions under drought conditions. Vogelmann red edge index (VOG REI) 1, chlorophyll index red edge (CIR), and red-edge normalized difference vegetation index (RE-NDVI) efficiently reflected moisture stress among the vegetation indices. Photochemical reflectance index (PRI) can be used as an indicator for early diagnosis of drought stress because hydrogen peroxide treatment showed higher values than untreated in the early stages of drought damage.

Impacts of long-term saline water irrigation on soil properties and crop yields under maize-wheat crop rotation

Saline water is widely used as an alternative water resource for agriculture to overcome the freshwater shortage in arid and semiarid regions. But long-term using of the saline water for irrigation would negatively affect soil properties and crop production, and the salinity of the irrigation water should be properly managed to reduce the risks. In this study, saline water with five levels of electrical conductivities (ECiw) at 1.3 (CK), 3.4, 7.1, 10.6, and 14.1 dS·m−1 were used to irrigate winter wheat and summer maize with annual double cropping system in the North China Plain (NCP) from 2006 to 2019, to decide the threshold value for long-term using saline water. Crop yields and soil salinity were continuously examined from 2006 to 2019, and soil physicochemical properties were monitored in 2018 and 2019 after 12 years’ saline water irrigation. Results showed that soil salinity in the 0100 cm layer could be maintained at a low level using saline water with ECiw at 3.4 dS·m−1. Soil salt accumulated in winter wheat seasons could be leached from the main root zone in the following summer maize seasons, which were rainy in this region due to the monsoon climate. No significant difference was observed in grain yields for treatment with ECiw at 3.4 dS·m−1 compared to CK treatment. The electrical conductivity of the saturated soil extract (ECe), soil pH, sodium adsorption ratio, and bulk density within the top soil layer of 030 cm increased with the increase in ECiw, whereas the soil organic carbon, porosity, macroaggregates (> 0.25 mm) content, and activities of catalase, urease and alkaline phosphatase decreased, indicating the long-term using saline water irrigation deteriorated soil properties. But the difference in soil properties between the treatment of ECiw at 3.4 dS·m−1 and the CK was not apparent. There were reductions below 5% in relative grain yields and soil quality index (SQI) with ECiw lower than 3.17 and 3.10 dS·m−1 compared with CK treatment, respectively. Comprehensive consideration to maintain a stable crop production and benign soil quality, ECiw of 3.10 dS·m−1 for long-term saline water irrigation was recommended as the safe utilization threshold in the NCP.

Agroecological assessment of short crop rotation on sod-podzolic soil

In the conditions of drained lands with unsatisfactory work of reclamation systems, in the Polissia zone it became possible to grow commercially attractive crops, in particular, such as winter rapeseed and corn for grain. A short-rotation crop rotation was analyzed: lupine — winter rapeseed — winter rye — corn, on the basis of which various variants of the fertilization system were studied, including by replacing litter manure with siderate and by-products of all crops in combination with the recommended for the zone and increased (intensive) mineral norms fertilizers. The goal of the task was to determine the optimal agrochemical support for grain crop rotation to obtain stable crop productivity and preserve soil fertility. It was noted that during the 2016–2020 research, during the growing season of agricultural crops, the reserves of productive moisture in the meter-long layer of drained sod-podzolic sandy soil decreased to 60–80 mm, that is, to a critical level. It was established that the overall productivity of the crop rotation depended on its saturation with corn, the grain yield of which was 6.01–7.13 t/ha on average over 5 years at different levels of organic and mineral nutrition. The highest yield of grain and fodder units from 1 ha of crop rotation area (4.23 and 4.52 tons, respectively) was obtained when by-products were applied together with an increased rate of mineral fertilizers (N67P84K91). It was established that the replacement of litter manure with the by-products of grain, leguminous and oilseed crops as an organic fertilizer, together with the use of the recommended (N45P56K61) and increased (N67P84K91) mineral fertilizer rates, does not reduce the productivity of crop rotation, ensures a deficit-free nitrogen balance and the annual accumulation of humus in the amount of 320 and 440 kg, respectively, which guarantees extended reproduction and increased soil fertility.

Identifying optimum residue levels for stable crop and water productivity and carbon sequestration under a conservation agriculture based rice-wheat system

To sustain food-production targets while reducing residue burning in the Indo-Gangetic Plains, adoption of conservation agriculture (CA) is desirable, amongst other potential adaptations. To identify the optimum residue levels for sustainable CA, the Agricultural Production Systems Simulator (APSIM) model was used to analyse 37 years (1984–2022) of diverse CA scenarios on productivity, sustainability and carbon footprints in the rice-wheat cropping system (RWCS). The study highlighted that APSIM has the capacity to capture the crop performance, phenology and CA scenario in RWCS. The scenario analysis indicated that maximum system productivity (SP) was recorded under higher residue (HR-9.33 t ha−1) followed by higher-medium residue (HMR-8.97 t ha−1) scenarios of CA, as compared to conventional tillage (CT-8.75 t ha−1). Stable productivity was achieved under CA. Sustainable yield index and sustainable value index were significantly higher under HR (0.83 and 0.79, respectively) followed by HMR. The soil organic carbon concentration is predicted to increase ∼30–95% in CA with a carbon sequestration rate of 0.1–0.37 t ha−1 yr−1. The system water productivity was highest under HR (3.68 kg ha−1 mm−1) which was ∼10% higher than CT. Overall, the study revealed that the APSIM model is efficient in capturing CA effects in South Asian RWCS and that the adoption of CA results in greater and stable yields, higher water productivity, and more carbon capture over the long term, while reducing production costs.

Multifarious microbial biostimulants promote growth in Arachis hypogaea L.

Plant Growth Promoting Rhizobacteria (PGPR), a microbial biostimulant has been widely studied to stimulate plant growth through induction of natural biological processes. However, lack of successful validation under open field remains a barrier to mark their standard in agriculture. Therefore, the aim of the research was to highlight the potential of PGPR biostimulants via in vitro studies and subsequently to demonstrate the in planta evaluation in oilseed crop, Arachis hypogaea L. (Groundnut) under pot and field trials. The two rhizobacterial strain was identified as Pseudomonas fluorescens and Bacillus subtilis by 16s rRNA gene sequence analysis. Both the strains were functionally screened for plant growth promoting traits. Pot and field trials were conducted where seeds were inoculated with PGPR biostimulants and harvested at 30 and 90 days. Biostimulant treatments were applied as single and co-inoculation in groundnut and the growth factors, biochemical parameters, yield, and seed quality were analyzed. The study inferred that the consortium of PGPR biostimulants significantly (p < 0.05) showed highest growth, photosynthetic pigments, nodulation status, leghaemoglobin content, yield attributes, and also biofortification of seed nutrients in oilseed crop under both pot and field conditions than un-inoculated control. This study supports the idea of the application of PGPR as microbial biostimulants through successful open field trial to facilitate its implementation as a feasible and potential agricultural product to synthetic fertilizers thereby influencing sustainable and stable crop production.

Crop production in Türkiye: trends and driving variables

Climate change and a rapidly increasing population boost the pressure on Türkiye’s cropping systems to increase crop production in order to meet rising food demand. It is unknown whether and in which direction trends and variability in harvested area and yield separately affect crop production in Türkiye. The objective of this study was to (1) quantify the long-term (2004–2020) trends of planting/harvested areas, yield and crop production for the 16 vital annual crops in Türkiye, (2) quantify the separate contribution of harvested area and yield on crop-specific production variability and (3) the potential of water and temperature-based remote sensing variables on capturing the variability of harvested areas and yield. The harvested area of the most grown crops (10 out of 16) such as wheat and barley showed a declining trend. However, the yield trend was increased for all of the study crops, which in some cases overcompensated for the decline in the harvested area on crop production. The harvested area showed a more robust explanatory power for production variability than yield except for the crops with higher breeding investments and subsidized by authorities such as wheat and sugar beet. The water-related remote sensing variables and combination of water and temperature variables largely explained the variability of the harvested area in Türkiye. In order to stabilize crop production in Türkiye, better and more efficient water management plans are crucial.

Understanding the spatio-temporal behavior of crop yield, yield components and weed pressure using time series Sentinel-2-data in an organic farming system

ContextOrganic farming has begun to represent a practical alternative for reducing the environmental impact of crop production and increasing biodiversity. In agricultural systems, the growing demand for stable crop production requires the adoption of useful tools for the sustainable intensification of agriculture. While organic farming systems face various drawbacks, which affect crop yield. Among the limiting factors, weed management is one of the most difficult aspects of organic farming. ObjectiveThe aim of the study was (i) to evaluate the effect of weed pressure on yield spatial variability (ii) to analyze the spatial variability of yield and yield components based on hand-sampled yield data (iii) to evaluate the ability of the most commonly used vegetation index (NDVI) derived from Sentinel-2 satellite platforms to understand within-field spatial and temporal variability during the crop cycle (iv) to evaluate the ability of the cluster analysis procedures on NDVI satellite data to identify, discriminate and map sub-areas with different yield, yield components, and weed pressure at the farm level in an organic farming system. MethodsRemote sensing techniques (Sentinel-2 images), vegetation index (NDVI), cluster analysis (Hierarchical clustering Ward’s minimum variance approach) and hand-sampled data (georeferenced yield and yield components field data) were used for understanding the spatio-temporal behavior of crops. Results and conclusionsThe cluster analysis of NDVI data from Sentinel-2 collected at eight different stages detected the crop spatial and temporal variability at an early stage. In an open field of 24 ha, an area of about 9 ha, showed a high weed level with a yield average value 78 % lower than the most productive cluster area. The yield components, especially the spike number per square meter, also recorded very low values, mainly due to the negative effect of the high presence of weeds (in particular oats), which reached average values of 250 g m-2. An area of 7.3 ha showed the highest yield at harvest with a yield value 45 % higher than the mean harvest data. The study highlights that from the early tillering stage to the booting stage the NDVI maps derived from the Satellite Sentinel-2 and clustered by Ward’s method represent the weeds distribution impact on crop yield and yield components and an early warning for the assessment of one of the most important limiting factors in organic farming. SignificanceSentinel-2 data and cluster analysis can improve an efficient assessment and management strategies in an organic farming agricultural system. Furthermore, the use of precision agriculture tools in organic farming can lead to a site‐specific management at the farm level and therefore a sustainable intensification of agriculture systems.

Technology of cultivation of annual Alexandrian clover (Trifolium alexandrinum)

The article discusses the results of research on a new technology we developed for the cultivation of an annual crop of Alexandrian clover (Trifolium alexandrinum), which includes a method of pre-sowing treatment of seeds with different terms and methods of sowing. Recently, along with agrotechnical measures to stabilize crop production, there is a need to cultivate non-traditional crops that are useful for human nutrition and health, and not the least role in this process is played by annual legumes. The short vegetation cycle and the intensive rate of crop formation allow them to be cultivated in repeated crops in places with favorable bio-climatic potential. Annual forage grasses have a variety of uses and purposes. In the zone of sufficient moistening, these are good fallow-grown crops. Annual legumes play an important role in creating a strong fodder base: in the summer, they are the main source of green feed production, they serve for the preparation of hay, haylage, silage, concentrated feed in the form of grass flour, cutting, full-fledged briquettes and pellets; annual legumes can also be used as a concentrated feed in the form of grain. Harvesting grasses in the early phases of the growing season and with multi-crop use with the use of artificial drying makes it possible to obtain a feed that is not inferior in total caloric content to oats and barley, and in protein content is significantly superior to them. Annual grasses are very diverse in terms of their agrobiological characteristics: they are widely used as preliminary crops on indigenous improvement lands and as links in the pasture conveyor. Our research conducted over four years (2017-2020) revealed that pre-sowing treatment of seeds of Alexandrian clover double and triple mixtures of PABA, the krezatsinom and infusion of chicory (against the background of preliminary stratification) provides low-cost, environmentally friendly way of pre-sowing stimulation of seeds of Alexandrian clover with simultaneous northering, adaptation, and selection of the best species for use in a specific region. Sowing clover for seeds is advantageously carried out with a width of 50 cm row spacing and seeding rate of 6 kg/ha. The optimal sowing date is beginning of March and the first week of September.

Plastic film-mulched ridges and straw-mulched furrows increase soil carbon sequestration and net ecosystem economic benefit in a wheat-maize rotation

The application of soil mulching has been widely used to increase crop production in arid, semi-arid, and sub-humid areas, with plastic film-mulched ridges and straw-mulched furrows (RFPS) proving to be more effective as compared with other soil mulching practices. However, few research studies have comprehensively assessed the impacts of RFPS on greenhouse gas (GHG) emissions, grain yield, net ecosystem carbon budget (NECB), and net ecosystem economic budget (NEEB) compared against the single practices of either plastic film mulching or straw mulching. A three-year field experiment was conducted on a wheat (Triticum aestivum L.)-maize (Zea mays L.) rotation field in the southern Loess Plateau, China. Four treatments were evaluated: (1) conventional flat planting without mulching (CK), (2) flat planting with plastic film mulching (PM), (3) flat planting with straw mulching (SM), and (4) RFPS. All mulching practices significantly increased wheat and maize yields as well as the seasonal cumulative carbon dioxide (CO2) emissions from soil respiration (Rs) and ecosystem respiration (Re) compared with CK. RFPS had the greatest annual grain yield and the greatest Rs for wheat seasons. The average annual NECB values for CK and PM were − 1.47 and − 1.05 Mg CO2-eq ha−1 yr−1, respectively, where the negative values indicated that the soil in CK and PM acted as a carbon (C) source. SM and RFPS acted as C sinks because of the straw C input, having average annual NECB values of 1.46 and 1.74 Mg CO2-eq ha−1 yr−1, respectively. PM, SM, and RFPS significantly increased the average annual NEEB by 31.4%, 70.5%, and 60.3%, respectively, compared with CK. Although RFPS had greater C input and grain yield income, it also had greater Rs, harvest removal C loss, and agricultural input costs, resulting in similar NECB and NEEB to what was observed with SM. Considering that the greatest grain yields were obtained with RFPS, this production practice should be a promising method for maintaining greater, more stable crop production, while increasing soil C sequestration and NEEB for the wheat-maize cropping system in dry semi-humid regions such as the southern Loess Plateau of China.

Addressing the Problem of Poverty through an International Cooperation Project: The Case Study of Agriculture Development by JICA in Cameroon

In this era of globalization, with social problems extending across social and geographical boundaries, partnerships between governments and international organizations are key to achieving the Sustainable Development Goals (SDGs). Agriculture is essential to reducing poverty in Cameroon. Since 2002, the Japan International Cooperation Agency (JICA) has contributed to agricultural development through various projects in Cameroon. However, research has not been conducted to determine the contributions of agricultural development to poverty reduction. The aim of this study is to outline current agricultural problems and international cooperation projects in Cameroon. A social inquiry involving the collection of qualitative and quantitative data was conducted to assess whether agricultural projects have contributed to increasing income and alleviating other multidimensional indicators of poverty amongst the beneficiaries. In this paper, we provide useful recommendations with respect to solving the problem of poverty and achieving the SDGs. The analysis revealed that agriculture projects have significantly contributed to an increase in income, wellbeing and standard of living of the project beneficiaries. African countries, such as Cameroon, need to address poverty by improving the agricultural sector because these nations cannot currently maintain a stable crop production. International cooperation in the agricultural sector can help to increase crop yields, incomes and quality of life.

Improvement of differentiated fertilizer application technology in the forest-steppe of Novosibirsk Priobye

In the article, the authors presented the results of the experimental work (2019-2021) to study the application of differentiated fertilizer application on cereal crops. Western Siberia is a region with risky conditions for stable grain crop production. Soft spring wheat and spring barley are the primary crops for food and feed. Soft spring wheat and spring barley are also characterized by a high demand for the most important environmental factors, which are highly variable. Current trends in precision farming imply the need for different technological operations. These operations are differentiated both in time and by individual crop rotation fields. At the same time, operations take more fully into account the bio-resource potential of cultivated agricultural enterprises. And these operations also take into account soil and terrain features, which are controlled by the aggregates and their links to technological operations. In the field, the authors used aggregates with differentiated application rates of fertilizers or crop protection products. The yield mapping is an element of precision farming technology. This technology is achieved by signal sensors on combined and onboard computers and GPS receivers during the harvesting period. An accurate map of the field, showing the characteristics of each field section, enables rational resource allocation and increases yields from each section of the field. The availability of digital maps ensures the optimization of fertilizer, seed, and water application to each section of the field. Under the conditions of the JSC Livestock Breeding Farm Irmen, Ordynsiky district, Novosibirsk region, the data are entered into the on-board computer of agricultural equipment going into the field, and innovative control of technological processes in crop production is carried out through GPS navigation. The work aims to improve the technology of the application of differentiated fertilizers to grain crops in the precision agriculture system under forest-steppe conditions in the Novosibirsk region Priobye. The research was carried out in 2019-2021 in the soil and climatic zone of drained forest steppe on leached chernozem at JSC Livestock Breeding Farm «Irmen» on spring wheat varieties Novosibirskaya 31, Licamero, as well as the spring barley variety Paustian. The use of differentiated fertilizer application contributes to an increase in grain yield parameters of spring wheat by 36% and of spring barley varieties by 28%. The study showed that differential fertilizer application contributes to the improvement of grain quality parameters of soft spring wheat.

Fallow replacement cover crops impact soil water and nitrogen dynamics in a semi-arid sub-tropical environment

Conventional dryland cropping systems rely upon frequent and lengthy fallow periods to conserve soil water and mineral nitrogen to stabilize crop production. However, this is associated with depletion of soil organic matter and decreased fallow efficiency. Intensifying cropping systems by planting cover crops has been touted as a means to stem soil organic matter loss and improve fallow efficiency. We investigated whether the manipulation of cover crop functional trait diversity and sowing proportions (utilizing Poaceae, Fabaceae, and Brassicaceae) could provide complementary functions that improve soil water and mineral N management during fallow. Grass-legume mixtures represented the best compromise between biomass production (> 4000 kg DM ha˗1), N retention (142 kg N ha˗1), N supply via biological N fixation (35 kg N ha˗1) and maintained an additional 70 mm of water at the end of fallow period. Regardless of functional trait type, cover crops increased N retention but maintained similar soil mineral N content at the end of fallow period. However, soil water effects were functional trait-specific, and there were significant soil water deficits with brassica-dominated cover crops. Soil water accumulation post cover crop termination was significantly higher in cover crops compared with conventional fallows, but the overall fallow efficiency was higher in the conventional fallow. This study demonstrates that cover crops are not universally beneficial, and careful selection of cover crop functional traits in mixtures could enhance fallow soil water and N management in semi-arid sub-tropical drylands.

Optimized cultivar deployment improves the efficiency and stability of sunflower crop production at national scale.

Crop simulation helps to analyze environmental impacts on crops and provides year-independent context information. This information is of major importance when deciding which cultivar to choose at sowing time. Plant breeding programs design new crop cultivars which, while developed for distinct populations of environments, are nevertheless grown over large areas during their time in the market. Over its cultivation area, the crop is exposed to highly diverse stress patterns caused by climatic uncertainty and multiple management options, which often leads to decreased expected crop performance. In this study, we aim to assess how finer spatial management of genetic resources could reduce the yield variance explained by genotype × environment interactions in a set of cropping environments and ultimately improve the efficiency and stability of crop production. We used modeling and simulation to predict the crop performance resulting from the interaction between cultivar growth and development, climate and soil conditions, and management practices. We designed a computational experiment that evaluated the performance of a collection of commercial sunflower cultivars in a realistic population of cropping conditions in France, built from extensive agricultural surveys. Distinct farming locations sharing similar simulated abiotic stress patterns were clustered together to specify environment types. We then used optimization methods to search for cultivars × environments combinations leading to increased yield expectations. Results showed that a single cultivar choice adapted to the most frequent environment-type in the population is a robust strategy. However, the relevance of cultivar recommendations to specific locations was gradually increasing with the knowledge of pedo-climatic conditions. We argue that this approach while being operational on current genetic material could act synergistically with plant breeding as more diverse material could enable access to cultivars with distinctive traits, more adapted to specific conditions.

Probabilistic modeling of crop-yield loss risk under drought: a spatial showcase for sub-Saharan Africa

Assessing the risk of yield loss in African drought-affected regions is key to identify feasible solutions for stable crop production. Recent studies have demonstrated that Copula-based probabilistic methods are well suited for such assessment owing to reasonably inferring important properties in terms of exceedance probability and joint dependence of different characterization. However, insufficient attention has been given to quantifying the probability of yield loss and determining the contribution of climatic factors. This study applies the Copula theory to describe the dependence between drought and crop yield anomalies for rainfed maize, millet, and sorghum crops in sub-Saharan Africa (SSA). The environmental policy integrated climate model, calibrated with Food and Agriculture Organization country-level yield data, was used to simulate yields across SSA (1980–2012). The results showed that the severity of yield loss due to drought had a higher magnitude than the severity of drought itself. Sensitivity analysis to identify factors contributing to drought and high-temperature stresses for all crops showed that the amount of precipitation during vegetation and grain filling was the main driver of crop yield loss, and the effect of temperature was stronger for sorghum than for maize and millet. The results demonstrate the added value of probabilistic methods for drought-impact assessment. For future studies, we recommend looking into factors influencing drought and high-temperature stresses as individual/concurrent climatic extremes.

WUSCHEL-related homeobox family genes in rice control lateral root primordium size

The development of a plastic root system is essential for stable crop production under variable environments. Rice plants have two types of lateral roots (LRs): S-type (short and thin) and L-type (long, thick, and capable of further branching). LR types are determined at the primordium stage, with a larger primordium size in L-types than S-types. Despite the importance of LR types for rice adaptability to variable water conditions, molecular mechanisms underlying the primordium size control of LRs are unknown. Here, we show that two WUSCHEL-related homeobox (WOX) genes have opposing roles in controlling LR primordium (LRP) size in rice. Root tip excision on seminal roots induced L-type LR formation with wider primordia formed from an early developmental stage. QHB/OsWOX5 was isolated as a causative gene of a mutant that is defective in S-type LR formation but produces more L-type LRs than wild-type (WT) plants following root tip excision. A transcriptome analysis revealed that OsWOX10 is highly up-regulated in L-type LRPs. OsWOX10 overexpression in LRPs increased the LR diameter in an expression-dependent manner. Conversely, the mutation in OsWOX10 decreased the L-type LR diameter under mild drought conditions. The qhb mutants had higher OsWOX10 expression than WT after root tip excision. A yeast one-hybrid assay revealed that the transcriptional repressive activity of QHB was lost in qhb mutants. An electrophoresis mobility shift assay revealed that OsWOX10 is a potential target of QHB. These data suggest that QHB represses LR diameter increase, repressing OsWOX10 Our findings could help improve root system plasticity under variable environments.

Metatranscriptomic Sequencing Suggests the Presence of Novel RNA Viruses in Rice Transmitted by Brown Planthopper.

Viral pathogens are a major threat to stable crop production. Using a backcross strategy, we find that integrating a dominant brown planthopper (BPH) resistance gene Bph3 into a high-yield and BPH-susceptible indica rice variety significantly enhances BPH resistance. However, when Bph3-carrying backcross lines are infested with BPH, these BPH-resistant lines exhibit sterile characteristics, displaying panicle enclosure and failure of seed production at their mature stage. As we suspected, BPH-mediated viral infections could cause the observed sterile symptoms, and we characterized rice-infecting viruses using deep metatranscriptomic sequencing. Our analyses revealed eight novel virus species and five known viruses, including a highly divergent virus clustered within a currently unclassified family. Additionally, we characterized rice plant antiviral responses using small RNA sequencing. The results revealed abundant virus-derived small interfering RNAs in sterile rice plants, providing evidence for Dicer-like and Argonaute-mediated immune responses in rice plants. Together, our results provide insights into the diversity of viruses in rice plants, and our findings suggest that multiple virus infections occur in rice plants.