PT  - JOURNAL ARTICLE
AU  - R.W. Rickman
AU  - C.L. Douglas, Jr.
AU  - S.L. Albrecht
AU  - L.G. Bundy
AU  - J.L. Berc
TI  - CQESTR: A model to estimate carbon sequestration in agricultural soils
DP  - 2001 Jul 01
TA  - Journal of Soil and Water Conservation
PG  - 237--242
VI  - 56
IP  - 3
4099  - http://www.jswconline.org/content/56/3/237.short
4100  - http://www.jswconline.org/content/56/3/237.full
AB  - The PC-based model for predicting tillage and crop rotation effects on organic carbon decomposition and storage in the soil as organic matter (OM) uses crop residue and root biomass production, tillage type and timing, and average temperature from existing c-factor files, created with the Revised Universal Soil Loss Equation (RUSLE). Residue nitrogen content and soil Layering information-including layer thickness, organic matter content, and bulk density-complete the input requirements for the model. Short-term trends of surface and remaining buried residue and Long-term trends in soil organic matter content, are computed for individual fields and cropping practices. The model was calibrated with soil organic carbon observations (converted to equivalent OM values) from plots with over 60 years of recorded management history including wheat/fallow with manure additions and wheat/fallow with stubble removal. Computations have a 95% confidence interval of +/-3.3 g OM kg−1 soil (0.33% OM). Comparison of OM calculations from the calibrated model with observed values from Lancaster, Wisconsin, and Lexington, Kentucky, produced mean residual errors ranging from -3.O to + 0.2 g OM kg−1 soil (-0.3 to + 0.02% OM.