Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 31, 2006
Publication Date: February 25, 2006
Repository URL: http://www.ars.usda.gov/sp2UserFiles/Place/36221500/cswq-0220-sadler.pdf
Citation: Sadler, E.J., Bausch, W.C., Fausey, N.R., Ferguson, R.B. 2006. Improving water use efficiency in agriculture. In: Proceedings International Fertilizer Industry Association (IFA)/Chinese National Chemical Construction Corporation (CNCCC) Agriculture Conference, Optimizing Resource Use Efficiency for Sustainable Intensification of Agriculture. February 27-March 2, 2006, Kunming, China. 2006 CDROM. Technical Abstract: In the 8-millenia history of irrigation, improving yield per unit water has probably always been the goal of irrigators. This ratio of yield per unit water was some 40 years ago named water use efficiency (WUE). This emphasized obtaining the maximum yield for a given irrigation amount, often by increasing fertilizer applications, usually of nitrogen (N). The implications of this approach are illustrated by 4 case studies. The South and Central Platte River valley case shows elevated groundwater nitrate-N levels from continuous irrigated, intensively managed maize. The US Corn Belt illustrates that intensive management of maize under rainfed conditions can also cause losses of nitrate-N. Research in the Lower Mississippi River Valley has shown ways to improve WUE of rice production; effects on nitrate or other fertilizer losses are under study. The fourth case study, in the Southeast Atlantic Coastal plain, illustrates spatial variation in WUE and N use efficiency. The case studies lead to a conclusion that simultaneous optimization of both inputs will be required for economically and environmentally sustainable agriculture.