NITROGEN RATE EFFECT ON YIELD AND NUTRIENT UPTAKE IN COTTON

S.H. Moore and G.A. Breitenbeck

ABSTRACT

Cotton (Gossypium spp.) was planted in 1990, 1991, and 1992, respectively, to determine the effect of nitrogen rate on crop growth rate, yield, and boll characteristics when produced on a Red River alluvial soil (Norwood silt loam, pH near 8.0) in central Louisiana. Seven rates of N ranging from 0 to 168 kg/ha in 28-kg increments were applied prior to planting in a randomized complete block design. The optimum N rate in 1990 was 124 kg/ha. Relevant results were not obtained in 1991 due to rainfall. The optimum rate in 1992 was 140 kg N/ha. The average optimum rate for the two representative years was 132 kg/ha which is nearly twice that commonly recommended. Increasing N rates resulted in higher concentrations of N, Ca, Fe, Mg, Mn, and Na. There was a clear decrease in concentration of S as N increased above 56 kg/ha. Boron and potassium decreased by over 40% between the lowest and highest N rates. The effect of N on Zn was significant but inconclusive. There was no effect of N rate on Al, Cu, Ni, or P.





[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page

Document last modified July 8, 2004