Submitted to: International Soil Tillage Research Organization Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: January 6, 2003
Publication Date: July 14, 2003
Citation: Torbert, H.A., Prior, S.A., and Runion, G.B. 2003. Impact of land use management decisions on C sequestration. p. 153. In Soil Management for Sustainability, International Soil Tillage Research Organization, 16th Triennial Conference Book of Abstracts, University of Queensland, Brisbane, Australia, July 14-18. Technical Abstract: A growing body of science indicates that C can be sequestered in soil as a result of changes to land management. Generally, this requires that land be taken out of cultivated agriculture, however, it has been postulated that the gains in soil C can be quickly eliminated with the return to cultivation. The objective of this study was to examine the impact of converting land back into cultivated agricultural management on C sequestration within different soil types. Soil samples from 9 soil depth increments (0-5, 5-10, 10-15, 15-30, 30-45, 45-60 60-75, 75-90, and 90-105 cm depth) were collected from a Marvyn sandy loam (fine-loamy, siliceous, thermic Typic Hapludults) and a Hannon clay loam (fine, smetic, thermic Chromic Halpuderts) which had been under different land management systems. The management systems included locations for both soil types that were forested and that had been managed as permanent pasture for greater than 40 years. Within the permanent pastures, locations that had been converted to continuous cultivation for 2 and 3 years were sampled. Within the sandy loam soil, land management locations which had been continuously cultivated were compared to locations that had been removed from cultivation and those that had been returned to cultivation after setting idle for 5 years. Soil samples were analyzed for total N, total C, soil C:N ratio, and bulk density. In addition, soil samples at the 0-5, 5-10 and 10-15 cm depth were analyzed for microbial biomass N (with a chloroform fumigation incubation technique) and microbial activity (with a dehydrogenase assay). Results from the soil analyses will be discussed.