Date of this Version Nitrate-nitrogen leached from the root zone
of land in intensive corn production is a major groundwater
contaminant in some of the intensively irrigated regions of the
western Cornbelt, including central and western Nebraska. To
obtain a clearer understanding of the amount and timing of
nitrate leaching losses from irrigated crops, 14 monolithic
percolation lysimeters were installed in 1989-1990 in sprinkler
irrigated plots at the University of Nebraska’s West Central
Research and Extension Center near North Platte, Nebraska. The
lysimeters were used to provide a direct measure of leachate
depth from continuous corn and a corn-soybean rotation. Both
cropping systems were sprinkler irrigated and used current best
management practices (BMPs) in the region for water and nitrogen
management. Leachate was collected from 1990 through 1998 and
analyzed for nitrate-N concentration. Results for the period
1993- 1998 are reported here. In the semi-arid climate of West-
Central Nebraska, the interact