Treatment with silicon fertilizer induces changes in root morphological traits in soybean (Glycine max L.) during early growth

Plant roots are key components of plant growth and development by taking up soil water and inorganic nutrients. Therefore, understanding root characteristics such as root length, root angle, root density, and root diameter is very important for improving crop productivity. Here, we investigate the effects of exogenous application of silicon on root morphological traits in two soybean cultivars (Taeseon and Pungsanaeul). The majority of root morphological traits evaluated show a significant (p < 0.05) effect of Si treatment. The exceptions to this trend were forks (p < 0.8677) and the mean link branching angle (p = 0.0632). In Taeseon cultivars, root morphological traits such as length (21.8%), diameter (19.3%), tips (32.8%), and projected area (34.4%) were significantly increased by Si treatment compared to plants that received no exogenous Si. Pungsanaeul cultivars showed a similar pattern. The length, mean diameter, tips, and projected area increased in soybean plants that received exogenous Si 21.3%, 13.6%, 25.9%, and 33.0%, respectively. In conclusion, exogenous Si application increased root length and root diameter, thereby increasing overall root biomass. Because Si application enhances root growth and development, we anticipate that it will increase soybean productivity by improving water and nutrient uptake. To verify these findings, additional experiments at field conditions are needed.