Residual maize fertilizer nitrogen availability to wheat on the southeastern Coastal Plain.
1994
Camberato J.J. | Frederick J.R.
In southeastern Coastal Plain soils, little emphasis is placed on adjusting N fertilization of a crop based on the residual N left from the preceding crop because of the perception of coarse-textured surface soils, winter rainfall in excess of evapotranspiration, and shallow-rooted crops. However, estimates of annual water surplus do not include a winter crop, which may reduce NO3-N leaching, nor consider current tillage practices, which enable deep rooting, and assimilation of subsoil NO3-N. This study was conducted to determine the contribution of N applied to a maize (Zea mays L.) crop to the N supply of a subsequent winter wheat (Triticum aestivum L.) crop. Wheat was grown following maize fertilized with various rates of N and poultry litter on a Rains/Lynchburg sandy loam soil complex (fine-loamy, siliceous, thermic Typic/Aeric Paleaquult) in 1990 and on a Noboco loamy sand (fine-loamy, siliceous, thermic Typic Kandiudult) in 1991. Maize fertilizer N increased soil NO3-N at the time of wheat planting. Residual N increased wheat dry matter, N content, and grain yield. An increase in maize N rate of 134 kg N ha-1 increased N supply to the subsequent wheat crop by approximately 15 kg ha-1 and increased wheat grain yield by 0.8 Mg ha-1. Poultry litter did not differ from fertilizer N in providing residual N to the wheat. This research demonstrates that previous crop fertilization rate may impact N supply to the subsequent crop, even on coarse textured Coastal Plain soils.
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