TY - JOUR T1 - Remote sensing for nitrogen management JF - Journal of Soil and Water Conservation SP - 518 LP - 524 VL - 57 IS - 6 AU - P. C. Scharf AU - J. P. Schmidt AU - N. R. Kitchen AU - K. A. Sudduth AU - S. Y. Hong AU - J. A. Lory AU - J. G. Davis Y1 - 2002/11/01 UR - http://www.jswconline.org/content/57/6/518.abstract N2 - Nitrogen application often dramatically increases crop yields, but N needs vary spatially across fields and landscapes. Remote sensing collects spatially dense information that may contribute to, or provide feedback about, N management decisions. There is potential to accurately predict N fertilizer need at each point in the field. This would reduce surplus N in the crop production system without reducing crop yield, which would in turn reduce N losses to surface and ground waters. Soil spectral properties (color) are related to soil organic matter and soil moisture levels, factors that influence the N-supplying ability of the soil. Plant spectral properties reflect crop N status and soil N availability, and they can be useful for directing in-season variable-rate N applications. Plant color may also be useful for assessing the adequacy of crop nitrogen supply achieved with a given nitrogen management practice. We outline the current status of these approaches, offer examples, discuss several N management contexts in which these approaches might be used, and consider possible future directions for this technology. ER -