Corn Yield and Economic Return with Nitrogen Applied Through Drip Tubing

Abstract

A two-year project was established near Sasser, GA, to determine corn (Zea mays L) yield response to subsurface (SSDI) and surface (SDI) drip irrigation systems at various nitrogen fertilizer rates. Nitrogen was applied through the drip system at two nitrogen levels in three split applications. Supplemental dry N fertilizer was applied on the soil surface at three nitrogen rates. Corn grain yield, test weight, nitrogen efficiency, and gross and net revenue were determined for each treatment. Rainfall received during the growing season was 10.6 and 16.0 inches for 2006 and 2007, respectively. Irrigation applied during the growing season was 14.8 and 8.5 inches during 2006 and 2007, respectively. Yield was greater in 2006 (190 bu/acre) compared with 2007 (167 bu/acre). There was no yield difference between SSDI and SDI at associated nitrogen treatments. Corn yields were lower at a base of 100 lbs N/acre (177 bu/acre) compared with a base of 200 lbs N/acre (206 bu/acre). Corn yield did not increase at rates above 200 lbs N/acre with either SSDI or SDI applications. Nitrogen efficiency was greater at lower nitrogen rates and decreased as nitrogen rates increased. Highest crop yield occurred at 200 lbs N/acre with average net revenue of $706/acre.