Spatial variability of soil organic carbon in grasslands: implications for detecting change at different scales
Conant, R.T.; Paustian, K.
Environmental Pollution 116(Suppl): S127-S135
2002
ISSN/ISBN: 0269-7491 PMID: 11833900 DOI: 10.1016/s0269-7491(01)00265-2
Accession: 011382271
Extensive data used to quantify broad soil C changes (without information about causation), coupled with intensive data used for attribution of changes to specific management practices, could form the basis of an efficient national grassland soil C monitoring network. Based on variability of extensive (USDA/NRCS pedon database) and intensive field-level soil C data, we evaluated the efficacy of future sample collection to detect changes in soil C in grasslands. Potential soil C changes at a range of spatial scales related to changes in grassland management can be verified (alpha=0.1) after 5 years with collection of 34, 224, 501 samples at the county, state, or national scales, respectively. Farm-level analysis indicates that equivalent numbers of cores and distinct groups of cores (microplots) results in lowest soil C coefficients of variation for a variety of ecosystems. Our results suggest that grassland soil C changes can be precisely quantified using current technology at scales ranging from farms to the entire nation.