Photo – Illinois Soybean Association

An ongoing study is investigating how conservation practices like sidedressing, along with environmental factors such as precipitation and temperature, affect soybean yields. The goal is to provide farmers with information to optimize their nitrogen management, crop productivity, and participation in conservation programs or carbon credit markets. 

Dr. Kaiyu Guan, the project lead, shared an update on recent findings. “Early-sidedress nitrogen applications have shown to result in higher yields compared to spring or fall applications. However, pre-growing-season precipitation plays a critical role in yield outcomes. Heavy rainfall before planting can lead to nitrogen leaching, particularly with fall-applied nitrogen, causing yield losses. In contrast, warmer temperatures during the growing season help close the yield gap between continuous corn and soybean-corn rotations by improving nitrogen mineralization and uptake. 

Additionally, vegetative-stage precipitation enhances the benefits of early-sidedress applications by improving nitrogen availability, though excessive rainfall can lead to leaching or ponding, which hampers plant growth.” 

As the study progresses, the team plans to collect more field measurements to better understand how different crop rotations and nitrogen management strategies affect soybean yields at a larger scale. The ongoing research will help farmers make more informed decisions about nitrogen use and crop rotation to optimize yield while benefiting the environment. 

Farmers interested in joining the study or learning more can visit the Field Advisor Research Hub.