Sustainable Soybean Production Research Articles

ChinaSoyArea10m: a dataset of soybean-planting areas with a spatial resolution of 10 m across China from 2017 to 2021

Abstract. Soybean, an essential food crop, has witnessed a steady rise in demand in recent years. There is a lack of high-resolution annual maps depicting soybean-planting areas in China, despite China being the world's largest consumer and fourth-largest producer of soybean. To address this gap, we developed the novel Regional Adaptation Spectra-Phenology Integration method (RASP) based on Sentinel-2 remote sensing images from the Google Earth Engine (GEE) platform. We utilized various auxiliary data (e.g., cropland layer, detailed phenology observations) to select the specific spectra and indices that differentiate soybeans most effectively from other crops across various regions. These features were then input for an unsupervised classifier (K-means), and the most likely type was determined by a cluster assignment method based on dynamic time warping (DTW). For the first time, we generated a dataset of soybean-planting areas across China, with a high spatial resolution of 10 m, spanning from 2017 to 2021 (ChinaSoyArea10m). The R2 values between the mapping results and the census data at both the county and prefecture levels were consistently around 0.85 in 2017–2020. Moreover, the overall accuracy of the mapping results at the field level in 2017, 2018, and 2019 was 77.08 %, 85.16 %, and 86.77 %, respectively. Consistency with census data was improved at the county level (R2 increased from 0.53 to 0.84) compared to the existing 10 m crop-type maps in Northeast China (Crop Data Layer, CDL) based on field samples and supervised classification methods. ChinaSoyArea10m is very spatially consistent with the two existing datasets (CDL and GLAD (Global Land Analysis and Discovery) maize–soybean map). ChinaSoyArea10m provides important information for sustainable soybean production and management as well as agricultural system modeling and optimization. ChinaSoyArea10m can be downloaded from an open-data repository (DOI: https://doi.org/10.5281/zenodo.10071427, Mei et al., 2023).

Assessing sustainable future of import-independent domestic soybean production in China: policy implications and projections for 2030

Soybean production, integral to sustainable agriculture and reliant on imports, faces vulnerability to international risk factors impacting domestic food security. The 2021 Central Rural Work Conference advocated strategic adjustments for sustainable soybean production amidst resource constraints, trade conflicts, and the lingering impact of COVID-19. This study scrutinizes the developmental framework of China’s soybean industry within current domestic policies. This paper uses the soybean sown area and soybean production in each province of China from 1995 to 2020 to measure China’s soybean concentration, production layout, and comparative advantage of regional scale, to analyze in depth the overall situation of China’s soybean production as well as the differences between regions, and to pave the way for the subsequent soybean production forecast. Further, taking the domestic soybean supply and demand situation in China in 2020 as the base period, while considering the growth values of soybean production under different scenarios, the potential forecasting model is utilized to estimate China’s soybean production under different scenarios. The results show that, in terms of inter-annual variability, revealing an upward trajectory from 1995 to 2020, with a shift to major soybean producing areas, notably in the northeast and the Huanghe-Huaihe-Haihe area. From inter-provincial changes, Soybean production on the left and right sides of the “Hu-Huanyong line” has significant heterogeneity; specifically, east of the “Hu-Huanyong line,” soybean production advantages are more obvious. Additionally, the study considered the actual planting situation of soybeans and envisaged two scenarios of compound planting and strip planting. The soybean production range in 2030 is expected to be 20.73–22.32 million tons and 21.15–27.55 million tons, with self-sufficiency rates varying from 18.57 to 19.98% and 18.95 to 24.68%, respectively. The research aims to provide a comprehensive understanding of China’s soybean industry and its potential trajectories, employing a model combining historical trends, policy analysis, and technological advancements. Results suggest a promising future with strategic adjustments in planting structures. Recommendations emphasize policymakers’ prioritization of technological investments and sustainable planting practices to achieve projected production targets. Policy interventions must address challenges tied to resource limitations, trade conflicts, and the ongoing COVID-19 effects, ensuring soybean industry resilience.

Identification of QTLs for symbiotic nitrogen fixation and related traits in a soybean recombinant inbred line population.

The genetic architecture of symbiotic N fixation and related traits was investigated in the field. QTLs were identified for percent N derived from the atmosphere, shoot [N] and C to N ratio. Soybean [Glycine max (L.) Merr.] is cultivated worldwide and is the most abundant source of plant-based protein. Symbiotic N2 fixation (SNF) in legumes such as soybean is of great importance; however, yields may still be limited by N in both high yielding and stressful environments. To better understand the genetic architecture of SNF and facilitate the development of high yielding cultivars and sustainable soybean production in stressful environments, a recombinant inbred line population consisting of 190 lines, developed from a cross between PI 442012A and PI 404199, was evaluated for N derived from the atmosphere (Ndfa), N concentration ([N]), and C to N ratio (C/N) in three environments. Significant genotype, environment and genotype × environment effects were observed for all three traits. A linkage map was constructed containing 3309 single nucleotide polymorphism (SNP) markers. QTL analysis was performed for additive effects of QTLs, QTL × environment interactions, and QTL × QTL interactions. Ten unique additive QTLs were identified across all traits and environments. Of these, two QTLs were detected for Ndfa and eight for C/N. Of the eight QTLs for C/N, four were also detected for [N]. Using QTL × environment analysis, six QTLs were detected, of which five were also identified in the additive QTL analysis. The QTL × QTL analysis identified four unique epistatic interactions. The results of this study may be used for genomic selection and introgression of favorable alleles for increased SNF, [N], and C/N via marker-assisted selection.

Zinc oxide and ferric oxide nanoparticles combination increase plant growth, yield, and quality of soybean under semiarid region

Zinc (Zn) and iron (Fe) malnutrition are global health challenges that need immediate attention. Hence, to address these issues, a two-pronged approach involving the development and application of novel Zn and Fe products for crop fertilization may be a potential solution. Therefore, zinc oxide (ZnO) (∼13.2 nm) and ferric oxide (Fe2O3) (∼15 nm) nanoparticles (NPs) were synthesized and characterized. Seven nutrients treatments viz, control, ZnO- NPs (25 mg kg−1), Fe2O3-NPs (25 mg kg−1), ZnO + Fe2O3-NPs (25 mg kg−1each), ZnSO4 (55.8 mg kg−1), FeSO4 (60.4 mg kg−1) and ZnSO4+ FeSO4 (55.8 and 60.4 mg kg−1) were arranged in five-time replicated Completely Randomized Design model to test the effectiveness of ZnO and Fe2O3 NPs in two soybean cultivars over conventional zinc sulfate (ZnSO4) and ferrous sulfate (FeSO4) fertilizers. The results indicated that the photosynthetic rate (Pn) and chlorophyll content increased (33.9–86.2%) significantly at the flowering stage with ZnO and Fe2O3 NPs applications, compared to their conventional counterparts. Likewise, the combined application of ZnO and Fe2O3 NPs reduced H2O2 production by 17–19% and increased the superoxide dismutase (SOD) and catalase (CAT) activities by 15–17% and 9.6–11.4% over the combined use of ZnSO4 and FeSO4, respectively. The normalized difference vegetation index (NDVI) showed an increase of 6.9–44.2% under ZnO and Fe2O3 NPs, as well as ZnSO4 and FeSO4. Furthermore, the combined application of NPs enhanced soybean seed yield by 4.6–18.3% compared to conventional Zn and Fe fertilizers. Concerning seed Zn and Fe density, conjoint application of ZnO and Fe2O3 NPs increases Zn by 1.8–2.2-fold and Fe by 19.22–22.58% over the combined application of Zn SO4 and FeSO4, respectively. While the application of NPs significantly decreased seed phytic acid concentrations by 7.3–59.9% compared to the control. These findings suggest that the combined application of ZnO and Fe2O3 NPs effectively enhances soybean productivity, seed nutrient density, and overall produce quality. Therefore, the combined application of ZnO and Fe2O3 -NPs in soybean can be a potential approach for sustainable soybean production and to reduce/arrest Zn and Fe malnutrition in a growing population.

Agro-Climatic Factors and Their Influence on Sustainable Soybean Production

This research explores the impact of intercropping corn and soybean, along with the combined effects of Azolla pinnata dose, the best soybean variety, and cytokinin concentration, on enhancing the physiology and agronomy of the plants. The study was conducted using 36 experimental units in a plot between soybean and corn. Various parameters were observed, including seed viability and vigor, soil analysis, nutrient content analysis of POC Azolla pinnata, temperature, air humidity, sunlight radiation, rainfall, pest infestation, diseases, and weeds. Additionally, plant height, leaf count, secondary branch count, total plant dry weight, leaf chlorophyll, leaf area ratio, leaf chlorophyll index, and stomatal conductance were measured. The data were analyzed using Djajasukanta and Sitompul-Guritno calculations, focusing on the average relative growth rate (RGR), average net assimilation rate (NAR), and root-shoot ratio (RSR). The results demonstrated that intercropping corn and soybean with the combination of Azolla pinnata dose, the best soybean variety, and cytokinin concentration had a positive impact on soybean production and quality. The Anjasmoro variety showed favorable outcomes in various parameters, such as plant height, leaf count, and branch count. Physiological leaf analysis revealed that the treatment combination with the Anjasmoro variety exhibited optimal photosynthetic rates and chlorophyll content, indicating higher photosynthesis efficiency. Moreover, the treatment with the Dega 1 variety displayed faster growth and efficient resource allocation, as evident from the high RSR value. The selection of the best soybean variety, Azolla pinnata dose, and cytokinin concentration can lead to sustainable improvements in soybean crop yield. These findings hold significant implications for agricultural management and enhancing food security.

Enhancing sustainable soybean production in Indonesia: evaluating the environmental and economic benefits of MIGO technology for integrated supply chain sustainability

Adopting MIGO Bio P 2000 Z in soybean cultivation in Indonesia has yielded significant advancements in sustainable agriculture. This innovative technology has demonstrated substantial potential in enhancing agricultural productivity. Environmental impacts of using MIGO Bio P 2000 Z include reduced reliance on chemical fertilizers, improved soil quality, positive contributions to greenhouse gas emissions reduction, and support for biodiversity conservation. Economically, implementing MIGO Bio P 2000 Z has increased soybean production, reduced fertilizer costs, higher incomes for soybean farmers, export opportunities, and investments in agricultural technology. While the primary focus is on economic impact, reducing chemical fertilizer use also benefits the environment by preventing pollution and soil degradation. Further, integrating MIGO Bio P 2000 Z into the soybean supply chain has bolstered supply sustainability, decreased dependency on soybean imports, and improved food security. Its positive effects include enhanced agricultural productivity, reduced environmental impact, and support for the well-being of farmers. Collaborative efforts, including government support, training, diversified markets, and strict monitoring, are essential for optimizing the technology's potential. Adopting MIGO Bio P 2000 Z in Indonesian soybean cultivation offers a sustainable and environmentally friendly approach to bolstering economic growth, food security, and the agricultural sector. In addressing challenges and enhancing the benefits, investing in training, market diversification, and regulations is vital while supporting farmers, especially small-scale ones. This holistic approach will secure Indonesia's soybean supply chain and strengthen the nation's agricultural resilience.

GENETIC ENHANCEMENT OF SOYBEAN (GLYCINE MAX L.) GERMPLASM FOR ADAPTABILITY AND PRODUCTIVITY

Soybean is an essential protein and oilseed crop, but environmental factors, such as photoperiod and altitude, highly influence its growth. Poor adaptability of soybean cultivars may result in a significant decrease in seed yield due to disruption of flowering or maturity. It is, therefore, vital to select cultivars adapted to specific regions of the world. Global climate change, causing increasing temperature and associated water deficit stress, may further challenge sustainable soybean production worldwide. Therefore, it is necessary to understand genetic responses in soybeans induced by environmental variables. This review highlights previous research showing how several quantitative trait loci (QTLs) activated by photo-thermal responses affected soybean flowering. We discuss cytogenetic stocks, including chromosome segment substitution lines, and their role in introgressing novel genes from wild soybeans. A review of genes showing responses to various environmental variables that affect soybean adaptability is also ensued, with putative functions suggested. These include gene response regulation to temperature and heat stress, identified via genetic mapping, and emerged as tools for developing adapted soybean cultivars.

The Potential and Prospect of Tidal Swamp Lands for Sustainable Soybean Production

The demand for food, particularly as a source of protein for the majority of Indonesia’s population, has not yet been satisfied by the country’s soybean production. For these reasons, the government works nonstop to intensify and extend soybean production in order to enhance productivity. Indonesia has a sizable amount of tidal marsh area (more than 700 000 ha) that is spread out throughout a number of islands, including Sumatera, Kalimantan, and Papua. The physical and chemical characteristics of the soil, such as water saturation in the root zones, a low pH, and a high Al concentration for soybean growth, are the main limitations of this land. However, the area may produce high soybean productivity (2.0 - 2.5 t/ha) with excellent management techniques. It is already possible to grow soybeans on tidal marsh lands using land and plant management techniques like fertilization, water management, amelioration, and tolerance varieties. In order to ensure sustained national soybean production in Indonesia and achieve self-sufficiency, tidal swamp areas have tremendous potential and chances for development.

Genome-Wide Association Analysis for Resistance to Coniothyrium glycines Causing Red Leaf Blotch Disease in Soybean.

Soybean is a high oil and protein-rich legume with several production constraints. Globally, several fungi, viruses, nematodes, and bacteria cause significant yield losses in soybean. Coniothyrium glycines (CG), the causal pathogen for red leaf blotch disease, is the least researched and causes severe damage to soybean. The identification of resistant soybean genotypes and mapping of genomic regions associated with resistance to CG is critical for developing improved cultivars for sustainable soybean production. This study used single nucleotide polymorphism (SNP) markers generated from a Diversity Arrays Technology (DArT) platform to conduct a genome-wide association (GWAS) analysis of resistance to CG using 279 soybean genotypes grown in three environments. A total of 6395 SNPs was used to perform the GWAS applying a multilocus model Fixed and random model Circulating Probability Unification (FarmCPU) with correction of the population structure and a statistical test p-value threshold of 5%. A total of 19 significant marker-trait associations for resistance to CG were identified on chromosomes 1, 5, 6, 9, 10, 12, 13, 15, 16, 17, 19, and 20. Approximately 113 putative genes associated with significant markers for resistance to red leaf blotch disease were identified across soybean genome. Positional candidate genes associated with significant SNP loci-encoding proteins involved in plant defense responses and that could be associated with soybean defenses against CG infection were identified. The results of this study provide valuable insight for further dissection of the genetic architecture of resistance to CG in soybean. They also highlight SNP variants and genes useful for genomics-informed selection decisions in the breeding process for improving resistance traits in soybean.

Approaches for sustainable production of soybean under current climate change condition

Soybean is an important cash crop, cultivated worldwide for food, oil and feed production. Soybean production worldwide in 2020 was 353.5 million metric tons. This plant however, faces many challenges due to climate change. Increase in temperature, drought, floods etc. are the outcomes of climate change. These have a clear negative impact on soybean cultivation. This ultimately leads to food insecurity and economic losses. This review focuses on approaches which can be employed to address the climate change associated challenges in sustainable soybean production. The approaches like genetic engineering, aeroponics, nanotechnology, development of cultivars, plant pigments and hormones usage can be opted to help combat the impact of changing climate. Management of soybean under adverse climate change conditions will increase the yield and bring agriculture based economic prosperity.

Effect of cashew (Anacardium occidentale) biochar on soil chemical properties and agronomy of soybean (Glycine max L. merril)

The experiments were conducted at the Teaching and Research Farm, Faculty of Agriculture, Nasarawa State University, Keffi, Shabu-Lafia during the 2018 and 2019 cropping seasons to evaluate the effects of different levels of biochar on soil properties, growth and yield of soybean. The experiments were laid in Randomized Complete Block Design (RCBD) with three replications. Biochar at the rates of 0, 4, 8 and 12 tons/ha were incorporated into the ridges of soybean at planting. The results showed that soil organic matter, organic carbon, total nitrogen, potassium, available phosphorus, calcium, sodium and base saturation decreased with soil layers. Soil pH (4.67 and 4.69), magnesium (1.52 and 1.62 cmol/kg), exchangeable acidity (0.67 and 0.75 cmol/kg) and cation exchange capacity (5.18 and 5.23 cmol/kg) increased with soil depth. Biochar at the rate of 12 tons/ha showed consistently the highest values of soil properties over other rates. The results also showed that biochar at the rate of 8 tons/ha recorded significantly (p<0.05) the tallest soybean plant height at 8 weeks (40.4 and 42.7 cm) and 10 (43. 0 and 49.2 cm) after planting in 2018 and 2019 cropping seasons respectively while the highest number of branches (4.5 and 4.5) was recorded in 2018 cropping season only. The results further revealed that biochar at the rate of 8 tons/ha recorded the highest weight per 100 seed (16.9 and 14.9 g) and seed yield (1304.0 and 1316.7 kg) per hectare in both cropping seasons. From the results of this study, it can be concluded that biochar at the rates of 12 and 8 tons/ha positively influenced soil and soybean plant parameters evaluated. Therefore, biochar at the rate of 8 tons/ha is considered as the optimum rate for sustainable soybean production in the study area.

RNA-seq Gene Profiling Reveals Transcriptional Changes in the Late Phase during Compatible Interaction between a Korean Soybean Cultivar (Glycine max cv. Kwangan) and Pseudomonas syringae pv. syringae B728a

Soybean (Glycine max (L) Merr.) provides plant-derived proteins, soy vegetable oils, and various beneficial metabolites to humans and livestock. The importance of soybean is highly underlined, especially when carbon-negative sustainable agriculture is noticeable. However, many diseases by pests and pathogens threaten sustainable soybean production. Therefore, understanding molecular interaction between diverse cultivated varieties and pathogens is essential to developing disease-resistant soybean plants. Here, we established a pathosystem of the Korean domestic cultivar Kwangan against Pseudomonas syringae pv. syringae B728a. This bacterial strain caused apparent disease symptoms and grew well in trifoliate leaves of soybean plants. To examine the disease susceptibility of the cultivar, we analyzed transcriptional changes in soybean leaves on day 5 after P. syringae pv. syringae B728a infection. About 8,900 and 7,780 differentially expressed genes (DEGs) were identified in this study, and significant proportions of DEGs were engaged in various primary and secondary metabolisms. On the other hand, soybean orthologs to well-known plant immune-related genes, especially in plant hormone signal transduction, mitogen-activated protein kinase signaling, and plant-pathogen interaction, were mainly reduced in transcript levels at 5 days post inoculation. These findings present the feature of the compatible interaction between cultivar Kwangan and P. syringae pv. syringae B728a, as a hemibiotroph, at the late infection phase. Collectively, we propose that P. syringae pv. syringae B728a successfully inhibits plant immune response in susceptible plants and deregulates host metabolic processes for their colonization and proliferation, whereas host plants employ diverse metabolites to protect themselves against infection with the hemibiotrophic pathogen at the late infection phase.

EFFECT OF DIFFERENT RATES OF BIOCHAR ON NODULATION AND YEILD OF SOYBEAN (Glycine max.L.merill)

The experiments were conducted at the Teaching and Research Farm, Faculty of Agriculture, Nasarawa State University, Shabu-Lafia Campus during 2018 and 2019 cropping seasons to evaluate the effect of different rates of biochar on nodulation and yield of soybean in Lafia, Southern Guinea Savanna of Nigeria. The experiments were laid in randomized complete block design (RCBD) with three replications. Biochar at the rates of 0, 4, 8 and 12 tons/ha was incorporated into ridges at planting. Four seeds of soybean were planted per hole at a spacing of 5cm between plants on four manually prepared ridges of 2 m long spaced at approximately 75cm. The seedlings were thinned to two plants after two weeks of planting (WAP). All data collected were subjected to analysis of variance (ANOVA) using GENSTAT statistical package while least significant difference was used to separate treatment means at 5% level of probability. The results obtained showed that biochar at the rate of 8 tons/ha significantly (p<0.05) produced the highest number of nodules (20.8 and 16.4), recorded the heaviest weight per 100 seeds (16.9 and 14.9g) and grain yield of soybean (1304.0 and 1316.7 kg/ha) in both cropping seasons. The results further revealed that the highest dose of biochar (12 tons/ha) in this study did not necessarily influence and increase any parameter tested except over the control (0.0 tons/ha) in both cropping seasons. Therefore biochar at the rate of 8 tons/ha is hereby considered to be the optimum rate for sustainable soybean production in the study area.

Foliar Application of Macro- and Micronutrients Improves the Productivity, Economic Returns, and Resource-Use Efficiency of Soybean in a Semiarid Climate

Inadequate nutrient management is one of the major challenges for sustainable soybean production in semi-arid climatic conditions. Hence, a 3-year (2015–2017) field experiment was conducted to assess the effect of foliar application of macro- and micronutrients on the growth, productivity, and profitability of soybean. Eight foliar nutrient sprays at the pod initiation stage—water spray (WS), 2% urea solution, 2% di-ammonium phosphate solution (DAP2%), 0.5% muriate of potash solution (MOP0.5%), 2% solution of 19:19:19 nitrogen phosphorus and potassium (NPK2%), and a 0.5% solution each of molybdenum (Mo0.5%), boron (B0.5%), chelated-zinc (Zn 0.5%) and no-foliar nutrition (NFN)—were compared with a basal-applied recommended dose of fertilizers (RDF: 30 kg N, 75 kg P, and 40 kg K ha−1) in a randomized block design (RBD), replicated three times. Foliar-applied chelated Zn@0.5% (Zn0.5%) at the pod initiation stage resulted in more pods per plants. In addition to Zn0.5%, urea2%, NPK2%, and B0.5% significantly improved the pods per plant over treatment by no-foliar nutrition (NFN). The RDF-supplied soybean subsequently sprayed with Zn0.5% produced the highest seed yield, which was 18.5–37.8% higher than that of NFN treatment Yield improvement due to the application of B0.5%, DAP2%, and urea2% varied between 19.2–23.7, 16.6–20.4 and 18.6–20%, respectively. Foliar nutrition showed the largest net returns from Zn0.5%. The water-use efficiency (WUE) and production efficiency increased by 18.4–37.6 and 34.9–37.5%, respectively, due to Zn0.5% over the efficiencies from NFN treatment. Monetary efficiency (ME) gains due to Zn0.5% were 24% higher, while ME efficiency gains due to urea2%, NPK2%, and B0.5% varied between 15–16%. Thus, this study suggested that the foliar application of 0.5% Zn and B, urea, NPK fertilizer, and DAP at 2%, along with RDF. is a profitable nutrient management option for quality soybean production in a semiarid region. However, nutrient partitioning, changes in soil chemical and biological indicators, and environmental aspects need critical examination in future studies.

Modeling the Impact of Climatological Factors and Technological Revolution on Soybean Yield: Evidence from 13-Major Provinces of China

In recent years, the changing climate has become a major global concern, and it poses a higher threat to the agricultural sector around the world. Consequently, this study examines the impact of changing climate and technological progress on soybean yield in the 13 major provinces of China, and considers the role of agricultural credit, farming size, public investment, and power of agricultural machinery from 2000 to 2020. Fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) are applied to assess the long-run effect, while Dumitrescu and Hurlin’s (2012) causality test is used to explore the short-run causalities among the studied variables. The results revealed that an increase in the annual mean temperature negatively and significantly affects soybean yield, while precipitation expressively helps augment soybean yield. Furthermore, technological factors such as chemical fertilizers accelerate soybean yield significantly, whereas pesticides negatively influence soybean yield. In addition, farming size, public investment, and power of agricultural machinery contribute remarkably to soybean yield. The causality results endorse that chemical fertilizers, pesticides used, agricultural credit, public investment, and power of agricultural machinery have bidirectional causality links with soybean yield. This study suggests several fruitful policy implications for sustainable soybean production in China.

GROWTH AND YIELD OF SOYBEAN (Glycine Max. L. Merril) AS INFLUENCED BY COMBINED APPLICATION OF BIOCHAR AND MICRONUTRIENT

The experiments were conducted at the Teaching and Research Farm, Faculty of Agriculture, Shabu–Lafia Campus of Nasarawa State University, Keffi, during the 2018 and 2019 cropping seasons to examine the integrated effects of biochar and micronutrient on the growth and yields of soybean. The experiments were laid in Randomized Complete Block Design (RCBD with three replications. Biochar at the rates of 0, 4, 8 and 12 tons/ha was incorporated into the ridges before planting the soybean seeds. Micronutrient at the rate of 0.0, 0.5 and 1 litre/ha was foliar applied two weeks after planting. All data collected were subjected to analysis of variance (ANOVA) using GENSTAT Statistical Package while least significant different (LSD) was used to separate treatment means at 5 % level of probability. The results revealed that biochar at the rate of 8 tons/ha, when combined with micronutrient at the rate of 0.5 litre/ha, recorded significantly (P<0.05) tallest soybean plant,the highest number of branches and nodules number per plant, heaviest weight of fresh nodules per soybean plant and grain yields (kg/ha) against other treatment combinations. The results also showed that the integration of the highest dose of biochar (12 tons/ha) with the highest dose of micronutrient (1 litre/ha) did not necessarily influence and increased soybean growth and yield parameters tested in this study. Therefore, integration of biochar at the rate of 8 tons/ha with micronutrients at the rate of 0.5 litre/ha is recommended for sustainable soybean production in the study area.

Improving irrigation, crop, and soil management for sustainable soybean production in Southern Brazilian lowlands

Lowlands have been cultivated with irrigated rice (Oryza sativa) in a monoculture cropping system for more than a century in southern Brazil. Shallow topsoil with high bulk density and deficient water infiltration favors the of production paddy rice; however, this condition does not favor species non-tolerant to flooding or oxygen restriction. Thus, soil and irrigation management may be necessary to raise the rice-soybean (Glycine max) rotation systems to sustainable levels. We carried out a two-year field experiment to assess the effects of irrigation treatments and soil management on soil physical properties, soybean growth, and grain yield in lowland systems. The experiment comprised a randomized block design with two factors and three replications. The main factor comprised the following irrigation treatments: sprinkler; surface, and rainfed. Four soil managements composed the second factor: conventional tillage (CT), no-tillage (NT), conventional tillage with raised-seedbed, and no-tillage with raised-seedbed. Soil physical properties, soil penetration resistance, crop parameters, grain yield and water productivity were evaluated. CT increased the soil penetration resistance near the soil surface layer. The highest soil bulk density at the 0.05-0.10 m layer in the CT reduces grain yield in rainfed soybean compared to NT. Supplementary irrigation increased soybean yield of about 36 % in years of uneven rainfall distribution. Sprinkler irrigation resulted in higher irrigated water productivity (90 %) compared to surface irrigation, contributing to a more sustainable increase in grain yield. Crop rotation in a no-tillage cropping scheme could improve the sustainability of diversified agriculture in lowlands.

Managing Micronutrients for Improving Soil Fertility, Health, and Soybean Yield

Plants need only a small quantity of micronutrients, but they are essential for vital cell functions. Critical micronutrients for plant growth and development include iron (Fe), boron (B), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), chlorine (Cl), and nickel (Ni). The deficiency of one or more micronutrients can greatly affect plant production and quality. To explore the potential for using micronutrients, we reviewed the literature evaluating the effect of micronutrients on soybean production in the U.S. Midwest and beyond. Soil and foliar applications were the major micronutrient application methods. Overall, studies indicated the positive yield response of soybean to micronutrients. However, soybean yield response to micronutrients was not consistent among studies, mainly because of different environmental conditions such as soil type, soil organic matter (SOM), moisture, and temperature. Despite this inconsistency, there has been increased pressure for growers to apply micronutrients to soybeans due to a fact that deficiencies have increased with the increased use of high-yielding cultivars. Further studies on quantification and variable rate application of micronutrients under different soil and environmental conditions are warranted to acquire more knowledge and improve the micronutrient management strategies in soybean. Since the SOM could meet the micronutrient need of many crops, management strategies that increase SOM should be encouraged to ensure nutrient availability and improve soil fertility and health for sustainable soybean production.

Economic Analysis of Biochar Use in Soybean Production in Poland

Soybean (Glycine max L.) is one of the most important crops grown globally. Biochar has been proposed as an alternative to aid sustainable soybean production. However, comprehensive studies that include both the economic aspects of soybean production and biochar are scarce. Poland, with an economy largely based on agriculture, is an interesting case to investigate the cost-effectiveness of using biochar in soybean production. We show that the use of biochar at rates of 40, 60 and 80 t/ha is unprofitable compared with a traditional soil amendment, such as NPK fertilization. The breakeven price for biochar to be economically viable should be USD 39.22, USD 38.29 and USD 23.53 for 40, 60 and 80 Mg/ha biochar, respectively, while the cost of biochar used for this experiment was USD 85.33. The payback period for doses of 40 and 60 Mg/ha was estimated to be three years. With a carbon sequestration subsidy of USD 30 per ton of CO2, the use of biochar may be profitable in the first year of soybean production. This is the first comprehensive economic analysis of the use of biochar in soybean production in Poland and one of the few published worldwide.

Nutrient Management for Soybean Crops

Soybean is one of the most important pulse crops in the world which supplies most of the protein and oil requirements. The efficient production of soybean crops is a constraint, with several biotic factors, abiotic factors, and crop management practices. Nutrient management is one of the important aspects for achieving higher production of crops. Effective nutrient management helps to assure the required nutrients needed for the plant without causing a significant decrease in the yield of crops. In addition to this, managing the nutrient efficiently helps the crop to cope with several types of biotic and abiotic stress. For soybean crop, altogether fifteen nutrients are needed, which comprises six macronutrients, namely, nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur, which are required relatively in large amounts, and nine micronutrients which include iron, boron, zinc, cobalt, copper, manganese, molybdenum, nickel, and chlorine. These nutrients can be supplied to the plants through soil incorporation or foliar spray of commercially available fertilizers. Nutrient requirements for soybean crops vary in concentration, and deviations can cause nutrient deficiency or toxicity in soybean crops. Nutrient availability to soybean crops depends on the available nutrients in the soil solution, the form of available soil nutrients, mode of uptake of nutrients, its interaction with other soil nutrients, soil chemistry, and method of fertilizer application. This review article explores essential nutrients for sustainable soybean production in relation to the role and functions of nutrients, required concentration, and visual syndrome shown during deficiency, including findings from several researches. The review article is aimed to guide soybean farmers for effective nutrient management and academicians in reviewing the literature in soybean nutrient management.