NUE and potential environmental outcomes associated with N application timing for corn
2019
- UW-Madison Soil Science
Project Media
Interest in improving nitrogen (N) use efficiency of corn production to increase farm profitability and reduce the deleterious effects of N on water quality has resulted in a greater focus on N application timing. A Midwestern study conducted in Illinois,
Indiana, Iowa, Minnesota, Missouri, Nebraska, North Dakota, and Wisconsin from 2014 to 2016 was designed to evaluate the profitability, potential N loss, and N use efficiency associated with at plant and split N application timing. In each year, two
sites were selected in each state representing a high and medium/low productivity
soil. Missouri had three sites in 2016. Selected sites had no manure history in at
least the three previous growing seasons. The previous crop was soybean at 43 sites,
corn at 5 sites, and sunflower at 1 site. The tillage system was either reduced tillage or no-till. All sites followed a standardized research protocol with regard to N treatments as well as soil and plant sampling. Nitrogen was applied at either planting or in a split application (40 lb N/a at plant plus sidedress), with N applications ranging from 0 to 280 lb N/a in 40 lb N/a increments. The economic optimum N rate (EONR) was calculated for each N application timing at each site.