Armstrong Memorial Research and Demonstration Farm
Authors: John E. Sawyer (Iowa State University) , Daniel W. Barker (Iowa State University)
Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there is interest in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Despite the fact that soybean is a legume, it readily utilizes soil inorganic N and will do so preferentially to symbiotic N2 fixation. Depending on the residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N in a mature soybean plant is derived from the soil. Also, soybean seems to require this soil derived N for high yield.
Keywords: Agronomy
How to Cite: Sawyer, J. E. & Barker, D. W. (2001) “In-Season Nitrogen Fertilization of Soybean”, Iowa State University Research and Demonstration Farms Progress Reports. 2000(1).