U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2008
Abstract
Nitrogen use efficiency (NUE) in production agriculture is often low, which results in losses of excess N to groundwater as NO3-N, to gaseous emissions of NH3 and N2O, and to N losses in surface runoff and erosion. Best management practices (BMPs) are needed to improve efficiency levels while maintaining proper nutrition for crops. Field studies designed to investigate potential BMPs are both time consuming and costly, and cannot cover all scenarios. Application of simulation models with N cycling components in conjunction with associated field investigations offers methodology that can help identify BMPs that show promise in increasing NUE, but at reduced cost and time expend. Examples from irrigated agriculture, rainfed agriculture, remote sensing, GIS, site specific agriculture, and precision conservation illustrate cases where models have been successfully used to identify potential BMPs to improve NUE and reduce leaching of NO3-N. However, credible BMP studies employing simulation tools need to proceed along a well-defined path involving model selection, model adaptation and calibration, sensitivity analyses, data requirements and availability, model application, and model results interpretation and limitations. These models could then be used with geographic information systems (GIS), global positioning systems (GPS), and remote sensing, to evaluate various BMPs, enabling them to assessment of efficient N uses at low costs and time expenditures.
Comments
Published in Nitrogen in the Environment: Sources, Problems, and Management, Second edition, ed. J. L. Hatfield & R. F. Follett (Amsterdam, Boston, et al.: Academic Press/Elsevier, 2008).
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