ARS | Publication request: NITROGEN ACCUMULATION IN COTTON FERTILIZED BY SUBSURFACE IRRIGATION AND GOSSYM/COMAX MANAGEMENT

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 1997
Publication Date: N/A

Technical Abstract: Cotton production, profitability, and environmental compatibility require good management of N and water. Precise applications of N and water by use of buried microirrigation and the GOSSYM/COMAX (GC) cotton growth model/expert system were investigated. Cultivar PD 3 was planted in May of 1991 through 1994 in peanut/cotton rotations and continuous cotton treatments. Each cropping-treatment split had eight sidedress-N and water treatments arrayed in a randomized complete block design with four replications. Each plot had eight, 0.96-m-wide rows. Microirrigation laterals were buried 0.30 m below the soil surface either directly under each row (IR) or under the alternate row middles (AM). Sidedress-N was applied via microirrigation in one 112-kg/ha application (STD); five, 22-kg increments (INC); or 11- to 22-kg/ha increments when required by GC. The rotation treatment did not significantly affect any of the measured parameters. The IR-STD was the highest in seed N content, and it was better than expected for excess N returned to the soil (32 kg/ha/yr) as well as lint production (2.02 Mg/ha/yr). The AM-GC treatment was superior to the IR-GC for uptake of N (113 vs. 76 kg/ha/yr). The AM-GC treatment would be the treatment of choice; it had a lint yield of 1.26 Mg/ha, conserved N better than the irrigated STD or INC treatments, and had less capital cost than the IR-GC.