There is a strong demand for accurate estimates of long-term changes in soil organic carbon(SOC)with different agricultural practices under different soil and climate conditions.A process and analytic model,K-model,in...There is a strong demand for accurate estimates of long-term changes in soil organic carbon(SOC)with different agricultural practices under different soil and climate conditions.A process and analytic model,K-model,including a non-compartmental algorithm of soil carbon decomposition,was developed to simulate the changes of SOC under different cropping and soil management practices.This study evaluates the performance of K-model by comparing its predictions on SOC with measurements and predictions of CENTURY model,which is widely used for the similar purposes.Both K-model and CENTURY can predict the dynamics of SOC when site-specific soil and climate data are used to initialize simulations.Very similar annual carbon decomposition rates were simulated by the single carbon pool K-model and the 3-carbon pool CENTURY model.However,compared with experimental measurements of SOC,K-model produces relative smaller errors than CENTURY(<0.1 kg C m-2 vs.0.08-0.48 kg C m-2,and within±5%vs.±5%-45%),mainly resulting from smaller biases of predicted crop production.When detailed site-specific soil and climate data are not available for initialization and feeding the running of model,K-model can still reasonably predict the dynamics of SOC with its auto-correction function,but CENTURY produces poor results.In comparison with measurements,K-model has improved capacities to predict the effects of chemical fertilizer,manure application,residue management and fallow on SOC dynamics.展开更多
基金financial support from EPCOR,Carbon Reduction Offset Project Ltd.and AARI,and critical review by Karen Haugen-Kozyra,Tom Goddard,Tony Brierley,Len Kryzanowski,Sheilah Nolan,Richard Harrow and Keith Anderson.
文摘There is a strong demand for accurate estimates of long-term changes in soil organic carbon(SOC)with different agricultural practices under different soil and climate conditions.A process and analytic model,K-model,including a non-compartmental algorithm of soil carbon decomposition,was developed to simulate the changes of SOC under different cropping and soil management practices.This study evaluates the performance of K-model by comparing its predictions on SOC with measurements and predictions of CENTURY model,which is widely used for the similar purposes.Both K-model and CENTURY can predict the dynamics of SOC when site-specific soil and climate data are used to initialize simulations.Very similar annual carbon decomposition rates were simulated by the single carbon pool K-model and the 3-carbon pool CENTURY model.However,compared with experimental measurements of SOC,K-model produces relative smaller errors than CENTURY(<0.1 kg C m-2 vs.0.08-0.48 kg C m-2,and within±5%vs.±5%-45%),mainly resulting from smaller biases of predicted crop production.When detailed site-specific soil and climate data are not available for initialization and feeding the running of model,K-model can still reasonably predict the dynamics of SOC with its auto-correction function,but CENTURY produces poor results.In comparison with measurements,K-model has improved capacities to predict the effects of chemical fertilizer,manure application,residue management and fallow on SOC dynamics.
