Corn Growth and Nitrogen Uptake with Furrow Irrigation and Fertilizer Bands

AbstractFurrow irrigation is commonly used to provide supplemental water to row crops. Alternate‐furrow irrigation has been proposed as a method to decrease deep percolation water losses as well as the leaching of fertilizer and pesticides. A study was conducted on a Ulm clay loam (fine, smectitic, mesic Ustic Haplargids) in 1994 and 1995 near Fort Collins, CO. Corn (Zea mays L.) growth and N uptake were measured under alternate‐furrow and every‐furrow irrigation water applications, each with fertilizer bands placed either in the row or in the furrow. Nitrogen‐15‐depleted (NH4)2SO4 fertilizer was used to distinguish plant uptake of fertilizer N from uptake of naturally occurring N. There were no differences in plant response to alternate‐furrow or every‐furrow irrigation water placement for the same amount of water applied. Greater fertilizer‐N uptake occurred with row placement than with furrow placement of N fertilizer. Early in the growing season, fertilizer‐N uptake from row placement was from 2 to 10 times the fertilizer‐N uptake from furrow placement. By the end of the growing season, the average total‐N uptake from row placement was 12% greater than for furrow placement. Placing the fertilizer in the nonirrigated furrow of the alternate‐furrow irrigation treatment decreased N availability by 20% compared with the average of the other treatments. If alternate‐furrow irrigation is used to increase water use efficiency in furrow‐irrigated fields, placing the N fertilizer in the nonirrigated furrow of the alternate‐furrow irrigation system could decrease N availability because of drier soil conditions in the nonirrigated furrow. Row placement of N fertilizer seems to be beneficial in both alternate‐furrow and every‐furrow irrigation applications.