Corn stover (the leaves and stalk residues of the corn plant left in a field after harvest) is considered one of the potential feedstocks for cellulose ethanol production. Traditionally, corn stover is left on land after harvest to improve soil fertility and also to improve soil organic carbon content. Removal of corn stover from the land for use in ethanol production can result in a loss of soil organic carbon, and may have adverse effects on soil fertility. According to Michigan State University scientists (in the United States), "growers wishing to maintain, or increase soil carbon levels for agronomic and environmental benefit will need to use carbon amendments such as manure, compost, or cover crops, to replace carbon removed with the corn stover". They found that compost and manure amendments increased to total soil organic carbon by 41% and 25%, respectively. The compost and manure amendments also decreased global warming potentials (GWP). Details of their findings are published in the Agronomy Journal (URL above).