Evaluation of Nitrogen and Irrigation Management for Corn Production using Water High in Nitrate

摘要: A field-calibrated computer model was used to study the interaction of nitrogen (N) and water management for corn (Zea mays L.) production on sandy soils in central Platte Valley Nebraska. Most irrigation this area is with pumped groundwater which at many locations contains from 10 30 ppm (or more) nitrate (NO3~-N). Simulation results were estimate effects management, N NO, -N concentration upon uptake by corn, efficiency fertilizer N, potential pollution NO3~-N. Nitrogen also partitioned according source (groundwater applied residual plus mineralized N). showed that: 1) strongly influenced amount applied, a lesser extent NO3~-N water. There strong these parameters determining uptake. 2) The very sensitive excess only slightly affected or 3) while had effect. In general, efficiencies higher more stable than efficiencies. 4) Excess increased sources under certain conditions. contribution large containing >10 primarily determined concentration. For 25 NO,~-N small applications extracted through lost due leaching. Additional Index Words: nitrogen, efficiency, pollution, partitioning Martin, D. L., G. Watts, L. N. Mielke, K. Frank, E. Eisenhauer. 1982. Evaluation using high nitrate. Soil Sci. Soc. Am. J. 46:1056-1062. G primary River eastern Currently, there are over 11,000 wells valley majority having pumping lifts <18 m. During last years increasing concentrations (NO3"~-N) have been found various parts (Spalding et al., 1978). Concentration may go above 40 few locations, ppm. At present ' Contribution Nebraska Agric. Exp. Stn., cooperation USDA-ARS. Published approval Director as Paper no. 6746 Journal Series, Stn. Received 29 Dec. 1981. Approved 22 Apr. 2 Research Associate, Professor, Agricultural Engineering Dep.; Scientist, USDA-ARS; Associate Agronomy Assistant Dep., respectively, University Nebraska, Lincoln, NE 68583. some municipalities faced prospect abandoning their domestic because exceed U.S. Public Health Service maximum standards sizable portion accumulation appears be result loss irrigated fields. problem generally most severe areas where furrow practiced loamy sands loam but occurs finer-textured soils. growing pressure farmers modify practices reduce leaching losses agricultural lands. Producers now question how best alter traditional minimize maintaining profitable yields. Interim guidelines established aid producers decision making process. However, much remains unknown about situations amounts available To supplement ongoing field research area, we what uptake, loss, might range nitrogen-water concentrations. utility threefold: (i) it provides better understanding change; (ii) helps clarify can modified environmental impact; (iii) projects practice effect affect yield. simulation studies must viewed relative sense, recognizing that they subject all errors approximations inherent attempts complex systems.