Author
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FOX, R. - PENN STATE UNIV |
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Walthall, Charles |
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Submitted to: American Society of Agronomy Monograph Series
Publication Type: Book / Chapter Publication Acceptance Date: 12/12/2002 Publication Date: N/A Citation: N/A Interpretive Summary: Nitrogen management in agriculture is a major concern because of its importance to crop production and because of losses of excess nitrogen leading to surface and ground water contamination. Methods to monitor crop nitrogen status including visual assessment, various forms of chemical analysis of plant elements, portable chlorophyll meters, soil testing and remote sensing have proven useful for improving nitrogen management and thus increasing yield and reducing excess nitrogen loss. A review of these methods indicates that they are becoming more accurate, easier to employ and increasingly more cost effective. The range of options available makes it possible to assess individual plants to entire fields. This review will serve as a primary reference to agriculture students, farmers, crop consultants, researchers and perhaps policy makers. Technical Abstract: Nitrogen management is a major concern because of its importance to crop production and because of losses of excess nitrogen to surface and ground water. Methods to monitor crop nitrogen status include visual assessment, tissue analysis for total N concentration and nitrate concentration, portable chlorophyll meters that rely on multispectral measurement of leaf transmittance, soil testing and remote sensing. Extrapolation of point measurements to whole field estimates is a major hurdle that is currently being overcome. The methods are becoming more accurate, easier to employ and increasingly more cost effective. New procedures are currently under investigation that may improve accuracy and scalability from leaves to field. This review will serve as a primary reference to agriculture students, farmers, crop consultants, researchers and policy makers. |
