Proceedings 2004

Indiana Crop Adviser Conference

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Nitrogen and the Environment

Agronomic Factors and Environmental Consequences of Nitrogen Management Practices

Profitable corn production is affected more by nitrogen (N) fertilization practices than by any other nutrient. At the same time, environmental consequences such as leaching of nitrate to ground and surface waters and denitification of nitrogen and nitrous oxide to the atmosphere are closely related to N management practices used by corn producers. Rate and time of application are the primary management practices having greatest impact on crop yield, economic return, and N loss to the environment. Research in Minnesota has shown greater N leaching losses and slightly reduced profit when applied N rates are higher than recommended. On the other hand, using N rates lower than recommended only slightly reduced N leaching losses while substantially reducing profit. Spring, preplant application of a recommended N rate to corn rotated with soybean reduced nitrate losses to subsurface drainage by 14% compared to late, fall-applied N. Adding nitrapyrin (N-Serve) to late, fall-applied N reduced nitrate losses 10% compared to not using nitrapyrin, but profit was still greatest with spring-applied N in a 10-year study.

Gyles Randall Professor, Soil Scientist
University of Minnesota

Biography:Gyles W. Randall is Professor and Soil Scientist at the University of Minnesota Southern Research and Outreach Center. A native of Wanamingo, Minnesota, Randall earned his B.S. and M.S. degrees from the University of Minnesota and Ph.D. degree from the University of Wisconsin. His research interests lie in soil fertility, tillage, cropping systems, and environmental quality as they relate to crop production. Specific research has centered on improved nutrient efficiency and management of fertilizers and animal manures in the development of best management practices (BMPs) to limit losses of nutrients to subsurface, tile drainage water.