Predicting longterm organic carbon dynamics in or

Authors: César Plaza Hero T Gollany Guido Baldoni Alfredo Polo Claudio Ciavatta

Publish Date: 2012/02/08

Volume: 12, Issue: 4, Pages: 486-493

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Abstract

The CQESTR model is a processbased C model recently developed to simulate soil organic matter SOM dynamics and uses readily available or easily measurable input parameters The current version of CQESTR v 20 has been validated successfully with a number of datasets from agricultural sites in North America but still needs to be tested in other geographic areas and soil types under diverse organic management systemsMeasured SOC levels declined over the study period in the unamended soil remained constant in the soil amended with crop residues and tended to increase in the soils amended with manure especially with solid manure Linear regression analysis of measured SOC contents and CQESTR predictions resulted in a correlation coefficient of 0626 P  0001 and a slope and an intercept not significantly different from 1 and 0 respectively 95 confidence level The mean squared deviation and root mean square error were relatively small Simulated values fell within the 95 confidence interval of the measured SOC and predicted errors were mainly associated with data scatteringThe CQESTR model was shown to predict with a reasonable degree of accuracy the organic C dynamics in the soils examined The CQESTR performance however could be improved by adding an additional parameter to differentiate between predecomposed organic amendments with varying degrees of stabilityThis work was partly supported by the VI National RDI Plan 2008–2011 of the Spanish Ministry of Science and Innovation AGL200909124 C Plaza is especially grateful to the Spanish Ministry of Science and Innovation for having supplied the funds which made possible his visit to the Columbia Plateau Conservation Research Center USDAARS Technical assistance by RW Polumsky and R Greenwalt at the Columbia Plateau Conservation Research Center is gratefully acknowledged

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