Wednesday, November 7, 2007
308-9

Effect of Rye Residue Removal and Interaction with Nitrogen Fertilization on Cotton Productivity.

Fernando Ducamp1, Francisco J. Arriaga2, Kipling S. Balkcom2, and Charles Mitchell1. (1) Department of Agronomy and Soils, Auburn University, 201 Funchess Hall, Auburn, AL 36849, (2) USDA-ARS, 411 S Donahue Dr, Auburn, AL 36832

Optimum nitrogen (N) rates for cotton depend on many variables including cover crops use. Utilization of winter cover crops (WCC) is a recommended practice for sustainable cotton cropping systems in the southeastern US, because of its benefits on soil physical and chemical properties. However, WCC biomass could also be harvested for alternative fuel use. This practice could modify cotton fertilization requirements under conservation systems. An experiment, in central Alabama, examined the effect of WCC biomass removal and cotton N rates on cotton productivity in 2006. Treatments were arranged in a split-plot design, with WCC residue management levels (no cover crop, rye residue removed and rye residue retained) in main plots and cotton N rates (0, 50, 100 and 140 kg.ha-1) in subplots. First year data showed higher cotton biomass yield, N uptake and higher plant and leaf N concentration at first square when rye residue was retained with respect to the other two residue management levels. Rye residue retained had the lowest leaf N concentration at mid bloom, and the highest cotton biomass yield and N uptake at cutout. All N treatments increased leaf N concentration at mid bloom and cotton biomass yield and N uptake at cutout. The soil N mineralized/immobilized between first square and cutout was not significantly affected by residue management levels. Seed cotton yield response to N varied across residue management levels with higher N rates required when residue was removed or retained with respect to no cover crop. Preliminary results suggest residue management levels affected cotton plant growth parameters and seed cotton yield response to N rates.

Back to Management Impacts on Soil Productivity and Crop Yields
Back to S06 Soil & Water Management & Conservation

Back to The ASA-CSSA-SSSA International Annual Meetings (November 4-8, 2007)