%0 Journal Article %T Rye cover crop and nitrogen fertilization effects on nitrate leaching in inbred maize fields %A Rasse, D. P. %A Ritchie, J. T. %A Peterson, W. R. %A Wei, J. %A Smucker, A. J. %J Journal of Environmental Quality %V 29 %P 298-304 %D 2000 %X
Nitrate leaching from maize (Zea mays L.) fields fertilized in excess of plant requirements continue to threaten water quality even though many agronomists have recommended reducing N fertilization rates to contain this environmental risk. Inbred maize has lower N uptake than conventional hybrid maize; therefore, inbred maize production exposes soils to even greater ground water pollution risks by nitrates. A 3-yr field experiment was conducted on sandy loam soils in southwestern Michigan to investigate the combined effects of N fertilization rates and rye (Secale cereale L.) cover crops on NO3 leaching in inbred maize fields. Inbred maize was fertilized at 0, 101, and 202 kg N ha−1. Annual NO3 leaching losses were 7 kg N ha−1 higher in fields fertilized at 101 kg N ha−1 than in nonfertilized controls. Annual NO3 leaching losses to ground water between May 1995 and April 1998 from lysimeters fertilized at 202 kg N ha−1 averaged 88 kg NO3-N ha−1. Rye interseeded with inbred maize fertilized at 202 kg N ha−1 sequestered from 46 to 56 kg ha−1 of excess fertilizer N. Rye scavenged little residual fertilizer N in plots fertilized at 101 kg N ha−1. Well established rye cover crops in 1996 reduced NO3 leaching by as much as 65 kg N ha−1 when the previous crop was fertilized with 202 kg N ha−1. Therefore, rye cover crops sequestered substantial amounts of soil NO3 in heavily fertilized inbred maize fields.
%R 10.2134/jeq2000.00472425002900010037x %M KBS.2677