Legume Genomics and Genetics 2026, Vol.17, No.1, 68-79 http://cropscipublisher.com/index.php/lgg 70 physiological parameters such as chlorophyll content and photosynthetic rate were occasionally measured using portable instruments to link physiological status with growth responses under different planting densities (Liao et al., 2022; Wang et al., 2023). Figure 1 Field plot layout showing uniform row spacing and contrasting plant distribution patterns (uniform vs. non-uniform) used to evaluate spatial effects on canopy development and yield (Adopted from Xu et al., 2021) 3 Effects of Planting Density on Soybean Growth Traits 3.1 Changes in plant height and stem diameter Planting density significantly influences soybean plant height and stem diameter, with higher densities generally promoting taller plants but thinner stems. Increased competition for light in dense populations stimulates stem elongation as plants strive to capture more sunlight, resulting in increased plant height. For example, studies have shown that soybean plants grown at higher densities exhibited greater heights compared to those at lower densities, with the tallest plants observed under intermediate to high density treatments (Ran et al., 2023; Xu et al., 2024). However, this elongation often comes at the expense of stem diameter, which tends to decrease as planting density increases due to limited resources and mechanical support constraints. Thinner stems can reduce lodging resistance, potentially affecting yield stability under adverse weather conditions (Wang et al., 2023). The interaction between planting density and row spacing also affects these growth traits. Narrower row spacing combined with high density can exacerbate stem thinning while promoting height increase, whereas wider spacing may moderate these effects by reducing intra-specific competition. Additionally, varietal differences influence how plant height and stem diameter respond to density changes; some genotypes maintain thicker stems even at higher densities due to stronger meristem regulation (Figure 2) (Li et al., 2024). Understanding these dynamics is crucial for optimizing planting configurations that balance plant architecture traits conducive to both high yield and lodging resistance.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==