Author
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Jaynes, Dan |
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Submitted to: Meeting Proceedings
Publication Type: Proceedings Publication Acceptance Date: 6/6/2014 Publication Date: 6/6/2014 Citation: Jaynes, D.B. 2014. Nitrogen use efficiency research in the United States Department of Agriculture. Meeting Proceedings. Tetrapartitle Meeting, June 2-6, 2014, Vancouver, Canada. Interpretive Summary: Technical Abstract: Activities over the past 25 years have markedly improved the N use efficiency of corn with only modest improvements for other U.S. crops such as wheat and cotton. Corn production is the major consumer of N fertilizer in the U.S. and a major contributor to offsite water contamination by agriculture, so this improvement in corn N use efficiency has been critical. Future progress in improving N use efficiency will require additional refinements in all aspects of the 4 R approach of N management for the all combinations of U.S. crops, soils, climates, and production systems. The greatest opportunity for greater N use efficiency is improving the synchronization between N availability in the soil and crop need. Sidedressing N just before peak crop demand or applying controlled release N sources could both improve synchronization, but much more research is needed to make both approaches easier, reliable, and economical for farmers. Current crop breeding and genetic engineering research has focused little on specifically improving how the plant accumulates or uses N. This has to change if significant progress is to be made in crop genetics for improved N use efficiency. As farmers gain most of their information from the private sector, progress in the judicial use of N fertilizer will require Ag retailers and crop advisors to become better educated in proper 4 R practices and incorporate these practices into their farm recommendations. Finally, even if N is managed to optimize economic return to the producer, reactive N will still be lost via water and air pathways from most cropping systems. Thus, methods need to be developed and deployed that can capture and remove this N before it impacts the environment. A huge void in current research is quantifying the effect of both in-field and field-edge practices for crop yield and environmental protection at the watershed scale. These studies are expensive and difficult to conduct, and by their very nature, need to be sustained for many years to accurately measure changes. Because no agency has sufficient resources for this undertaking, these efforts will require coordination among numerous federal and state agencies, agricultural and environmental groups, and farmers. |
