Potential environmental effects of corn (Zea mays L.) stover removal with emphasis on soil organic matter and erosion

Recent concerns about CO2 emissions and global warming have prompted renewed interest in using corn stover for energy production. Lack of markets, concerns about sustained soil productivity, and lack of commercial conversion technologies have spread harvest of corn residues for this purpose. This paper reviews existing literature to evaluate the major precluded the wide environmental impacts potentially associated with stover harvest from reduced tillage corn production sites. Issues of greatest concern are erosion and soil organic carbon (SOC) dynamics, the latter both for its role in soil quality and yield and for global carbon cycle implications. About half of the literature examined concerned research in the United States, many publications described research activities conducted for decades, and major soil types in corn producing regions were well represented. Regional differences were primarily temperature and rainfall effects on stand establishment and yield, with potential feedback effects on SOC. Several research papers discussing the effects of residue harvest were found, but few field studies were found that explicitly studied the effects of corn stover harvest and most discussions acknowledge potential tradeoffs among beneficial and adverse effects. It was concluded that more information is needed on several topics to determine potential long-term effects of residue harvest, including (1) erosion and water quality, especially pesticides and nitrate, (2) rates of transformation of different forms of SOC, (3) effects on soil biota, and (4) SOC dynamics in the subsoil. (C) 2002 Elsevier Science B.V. All rights reserved.