%0 Journal Article %T Managing soil carbon and nitrogen for productivity and environmental quality %A Sanchez, J. E. %A Harwood, R. R. %A Willson, T. C. %A Kizilkaya, K. %A Smeenk, J. %A Parker, E. %A Paul, E. A. %A Knezek, B. D. %A Robertson, G. P. %J Agronomy Journal %V 96 %P 769-775 %D 2004 %X
In this study, we investigated the impact of cropping system management on C and N pools, crop yield, and N leaching in a long-term agronomic experiment in Southwest Michigan. Four management types, conventional (CO), integrated fertilizer (IF), integrated compost (IC), and transitional organic (TO) were applied to two crop sequences, a corn (Zea mays L.)-corn-soybean [Glycine mar (L.) Merr.]-wheat (Triticum aestivum L.) rotation and continuous corn, which were grown with and without cover crops in the IF, IC, and TO managements. Using compost as a fertility source and reducing the use of herbicides and other chemicals resulted in long-term changes in soil organic matter pools such TO greater than or equal to IC > IF greater than or equal to CO for total C and N and for the labile C and N measured through aerobic incubations at 70 and 150 d. Mineralizable N varied within the rotation, tending to increase after soybean and decrease after corn production in all systems. Corn yield was closely associated with 70-d N mineralization potential, being greatest for first-year corn with cover and least for continuous corn without cover under all management types. Although the TO and IC systems produced the lowest yield for second-year or continuous corn, the combination of soybean and wheat plus red clover (Trifolium pratense L.) always supported high yield for first-year corn. Fall nitrate level and nitrate leaching were higher for commercially fertilized corn than for any other crop or for compost-amended corn.
%R 10.2134/agronj2004.0769 %M KBS.2479