Soybean Response to Nitrogen Application Across the U. S.
2018
- Department of Agronomy, University of Wisconsin Madison
Project Media
U.S. soybean [Glycine max (L.) Merr.] production has increased by 60% from 1996 to
2016 due to a 30% increase in area planted to soybean, and due to better genetics and
improved crop management practices. While these historic seed yield increases have
been substantial, U.S. soybean producers continually search for opportunities to optimize
crop management and increase soybean seed yield, including applying fertilizer
N to soybean.
Soybean has a large nutrient requirement throughout the growing season, and has an
especially high N requirement due to its seed protein content that averages about 40%
based on seed dry weight (Bellaloui et al., 2015). Soybean N requirements peak in the
R3 to R6 growth stages (Gaspar et al. 2017; Harper, 1974). The N requirement of soybean
is generally fulfilled by biological nitrogen fixation (BNF) plus N uptake from soil
(Salvagiotti et al., 2008). However, BNF activity can be limited by a number of environmental
conditions such as low soil moisture, extremes of soil pH and temperature, and
soil compaction, any of which can result in insufficient N supply to the soybean plants
(Purcell and King, 1996).
Proceedings