Legume Genomics and Genetics 2024, Vol.15, No.6, 303-314 http://cropscipublisher.com/index.php/lgg 309 7.2 Biological inoculants for soybean growth Biological inoculants, particularly those involving symbiotic relationships with nitrogen-fixing bacteria, are vital for improving soybean growth and yield. The use of Bradyrhizobium spp. and Azospirillum brasilense as inoculants has shown significant benefits. For example, co-inoculation with these bacteria increased nodule number, dry weight, and grain nitrogen content, leading to a 47% increase in pods per plant and a 12% increase in yield compared to single inoculation methods (Brignoli et al., 2023). Furthermore, improvements in Biological Nitrogen Fixation (BNF) through the selection of effective bradyrhizobia strains and advanced inoculation techniques can significantly enhance soybean production. These biological enhancements are essential for sustainable soybean cultivation, especially in low-nitrogen soils. 7.3 Potential of marker-assisted selection in yield improvement Marker-assisted selection (MAS) has shown great potential in improving soybean yield by enabling the precise selection of desirable traits. Context-specific MAS (CSM) has been particularly effective, allowing for the detection of yield quantitative trait loci (QTL) within specific genetic and environmental contexts. This approach has led to statistically significant yield gains of up to 5.8% in selected subline haplotypes (Sebastian et al., 2010). Additionally, genomic selection (GS) using advanced models such as ridge regression Best Linear Unbiased Predictor (rrBLUP) has demonstrated high accuracy in selecting agronomic traits, further enhancing yield potential (Ravelombola et al., 2021). The integration of MAS and GS in breeding programs can accelerate genetic improvement and optimize soybean yield. 8 Climate Resilience and Adaptation Strategies 8.1 Impact of climate change on soybean yield Climate change poses significant challenges to soybean yield, with varying impacts depending on the region and specific climatic factors. In Southern Brazil, future climate scenarios predict increased temperatures and elevated atmospheric CO2 levels, which can affect soybean yields. Studies using crop-model ensembles have shown that without adaptation, soybean yields are likely to decrease due to increased temperature stress and altered precipitation patterns (Battisti et al., 2018). Similarly, in Northern Ghana, climate change is projected to reduce soybean productivity by 3% to 13.5%, although elevated CO2 levels could potentially offset these negative impacts, leading to increased productivity in some scenarios (MacCarthy et al., 2022). In the Southeastern United States, future climate scenarios predict a decrease in soybean yields by 1% to 13% due to temperature and moisture stresses (Lychuk et al., 2017). These findings highlight the critical need for effective adaptation strategies to mitigate the adverse effects of climate change on soybean production. 8.2 Agronomic adaptations for climate variability Agronomic adaptations are essential to enhance soybean resilience to climate variability. In Southern Brazil, optimal sowing dates, cultivar maturity groups, and planting densities have been identified as key strategies to improve soybean yields under future climate scenarios. For instance, sowing soybean on October 15 and using cultivar maturity group 7.8 with a planting density of 50 plants/m² resulted in higher yields across different climate scenarios (Battisti et al., 2018). In Northeast China, delaying sowing dates and selecting appropriate cultivars have been shown to mitigate the negative effects of climate change on maize yields, suggesting similar strategies could be effective for soybean (Zhang et al., 2020a). Additionally, in the U.S. Corn Belt, adapting planting dates and varieties has been found to increase crop yields and maintain soil organic carbon levels, thereby enhancing agroecosystem resilience (Zhang et al., 2020b). These adaptive practices demonstrate the importance of optimizing genotype-environment-management interactions to sustain soybean production under changing climatic conditions. 8.3 Role of conservation agriculture in climate resilience Conservation agriculture plays a crucial role in building climate resilience for soybean production. Practices such as crop diversification, reduced tillage, and improved water management can enhance soil health and water use efficiency, thereby increasing crop resilience to climate stressors. In Madhya Pradesh, India, intercropping
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