Soil organic carbon content and composition of 130-year crop, pasture and forest land-use managements

Conversion of former agricultural land to grassland and forest ecosystems is a suggested option for mitigation of increased atmospheric CO2. A Sharpsburg prairie loess soil (fine, smectitic, mesic Typic Argiudoll) provided treatments to study the impact of long-term land use on soil organic carbon (SOC) content and composition for a 130-year-old cropped, pasture and forest comparison. The forest and pasture land use significantly retained more SOC, 46% and 25%, respectively, compared with cropped land use, and forest land use increased soil C content by 29% compared with the pasture. Organic C retained in the soils was a function of the soil N content (r=0.98, P