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Nitrogen Use Efficiency

Soil organic matter increases crop yield amount and stability. Soil organic matter – not nitrogen fertilizer – is the largest source of crop nitrogen uptake and environmental nitrogen loss. For example, approximately 10% of Iowa corn acres are non-responsive to nitrogen fertilizer in any given year despite yields that exceed regional averages- however, predicting those acres is extremely challenging.

To increase nitrogen retention and nitrogen use efficiency, we must improve our understanding of the processes that control inorganic nitrogen fertilizer transformation to soil organic matter, and subsequent re-transformation of soil organic matter back to crop-available inorganic nitrogen (a process known as ‘mineralization’).

Nitrogen Use Efficiency
Funding Organization(s):
Israel-US Bi-National Agricultural Research & Development program (BARD)
Iowa Department of Agriculture and Land Stewardship
Leopold Center for Sustainable Agriculture
National Oceanic and Atmospheric Association
National Science Foundation
United Soybean Board
United States Department of Agriculture
Principal Investigators
William T. Frankenberger Professorship in Soil Science
Castellano, Michael
2104l Agronomy 716 Farm House Ln
(515) 294-3963