Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 7/9/2004
Publication Date: 7/25/2004
Citation: Sainju, U.M., Whitehead, W.F., Singh, B.P. 2004. Tillage, cover crops, and nitrogen fertilization effects on cotton and sorghum yields and nitrogen uptake[abstract]. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. Paper No. 3396. Interpretive Summary:
Technical Abstract: Production practices that sustain cotton (Gossypium hitsutum L.) and sorghum [Sorghum bicolor (L.) Moench] yields and improve soil and water qualities remain a challenge in the southeastern US. We examined the influence of three tillage practices [no-till (NT), strip till (ST), and chisel till (CT)], four cover crop management systems [nonlegume: rye (Secale cereale L.) (R), legume: hairy vetch (Vicia villosa Roth) (V), rye and hairy vetch mixture (RV), and no cover crop (winter weeds) (C)], and three N fertilization rates (0, 60 to 65, and 120 to 130 kg N ha-1) on yields and N uptake of cotton and sorghum. Experiment was conducted on a Dothan sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) from 1999 to 2003 in central GA. Cotton lint yield was 10 to 47% greater in NT with R than in NT with V, CT with V or RV, and ST with or without cover crops. Similarly, lint yield was 15 to 91% greater in NT with 60 kg N ha-1 than in ST and CT with or without N rates in 2000. In contrast, cotton biomass (stems + leaves + seeds + lint) yield and N uptake were 22 to 81% greater in ST than in CT in 2000 and in NT, ST, and CT in 2002. Although lint yield decreased, biomass yield, N concentration, and N uptake were greater with V and RV than with C and R in 2000 and 2002. Sorghum grain and biomass (stems + leaves + grain) yields and N uptake were 35 to 45% greater in ST and CT than in NT and 18 to 66% greater in V and RV with or without N rates than in C and R with 0 and 65 kg N ha-1 in 2001. Conservation tillage practices, such as NT and ST, with a mixture of legume and nonlegume cover crops, such as RV, and 60 to 65 kg N ha-1 can sustain cotton and sorghum yields and N uptake, with reduced potentials for soil erosion and N leaching.