Effect of Split N-fertilizer applications on Drainage Water Quality and NOb3s-N Leaching, February 1990

(1990) Effect of Split N-fertilizer applications on Drainage Water Quality and NOb3s-N Leaching, February 1990. Iowa State University

Preview

PDF effects_split_fertilizer_apps_drainage_water_qal_leaching_1990_OCR_.pdf File Size:7MB

Abstract

Two experimental plots, each drained by a single subsurface tile line and having an area of about 0.6 ac, were established at the Agronomy and Agricultural Engineering Research Center near Ames, Iowa. These two plots under conventional tillage have been planted to continuous com since 1984. To provide permanent access to the tile lines, 152 mm deep sumps were dug to intercept the tiles, sumps were installed to permit access for sampling drainage water for NO3-N analysis and flow measurements. Experimental plots J. were again planted to com in May 1988 using conventional tillage. Three applications of N-fertilizer totaling 112lb/ac were applied (first application of 22lb/ac was made at the time of planting, a second application of 45lb/ac was made in June, and third application of 45lb/ac was made in July). Soil-water samples were taken from various depths using piezometers and were analyzed for NO3-N by using a Technicon Autoanalyzer II system in the chemistry laboratory of the Agricultural Engineering Department.