Dr. Jeremy Ross

Extension Agronomist - Soybean Professor|University of Arkansas System Division of Agriculture

2023 Abstract - SOYBEAN YIELD RESPONSE TO NITROGEN AND SULFUR FERTILIZATION: FINDINGS FROM A NATIONAL COLLABORATION: Research on the effect of nitrogen and sulfur fertilization on seed yield of soybean has been done for years. However, soybean yield response to nitrogen and sulfur fertilizer applications remains inconsistent. This lack of consistent results could be due to the lack of standardized plot designs and a lack of understanding of the plant nutrition processes affecting grain yield. Twenty-six field trials in twelve states across the US tested five fertilization strategies that combined nitrogen and sulfur at different rates and timings. The objective of this study was to examine soybean seed yield response to nitrogen and sulfur across different environments and assess seed yield, plant N status, and the contribution of nitrogen fixation and soil nitrogen have on crop nutrition. For most locations, nitrogen and sulfur fertilization did not significantly increase soybean grain yield. Due to the high uncertainty in treatment response in the nitrogen treatments, nitrogen fertilization is unlikely to increase soybean grain yield.