Submitted to: Extension Reports
Publication Type: Experiment Station
Publication Acceptance Date: 1/1/2007
Publication Date: 3/30/2007
Citation: Balkcom, K.S., Arriaga, F.J., Mitchell, C.C., Delaney, D.P., Bergtold, J.S. 2007. Nitrogen Fertilizer Source, Rates, and Timing for a Cover Crop and Subsequent Cotton Crop. In: Lawrence, K.S., Monks, C.D., Delaney, D.P., editors. 2006 Cotton Research Report, Alabama Agricultural Experiment Station, Research Report No. 30. p. 27-28.
Technical Abstract: The objectives were to compare N fertilizer sources, rates, and time of application for a rye winter cover crop to determine optimal biomass production for conservation tillage production, compare recommended and no additional N fertilizer rates across different biomass levels for cotton, and determine the effect of residual N applied to the cover crop across two N fertilizer rates for cotton. Nitrogen sources, rates, and time of application were implemented at the Wiregrass Research and Extension Center (WREC) in Headland, AL. Biomass cover treatments were arranged in a split-split-plot design with 4 replications. At cotton planting, the eight row plots were split with one side receiving 90 lb N ac-1 at sidedress and the other side receiving no additional N. First year rye biomass results indicate that N fertilizer source or time of application had no effect on measured biomass levels. Biomass production was maximized at 60 lb N ac-1 for commercial fertilizer and 2 tons poultry litter ac-1. Plant heights were greatest following poultry litter application compared to no N applied. The highest rate of poultry litter produced the greatest plant biomass compared to no additional N or any of the commercial fertilizer rates. Most of the cover crop N rates required additional N to maximize plant heights and biomass at mid-bloom based on the response to 90 lb N ac-1 applied to the cotton at sidedress. The addition of 90 lb N ac-1 benefited the cotton crop, which was evident by the substantial increase in lint yields observed, regardless of the cover crop N rate. Interestingly, 3 tons of poultry litter ac-1 applied to the cover crop resulted in similar yields to 90 lb N ac-1 at sidedress with no N applied to the cover crop. The continuation of this experiment will provide information related to the interactive effects of cover crop and cash crop fertilization.