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CQESTR Simulation of Management Practice Effects on Long‐Term Soil Organic Carbon
Author(s) -
Liang Y.,
Gollany H. T.,
Rickman R. W.,
Albrecht S. L.,
Follett R. F.,
Wilhelm W. W.,
Novak J. M.,
Douglas C. L.
Publication year - 2008
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2007.0154
Subject(s) - crop residue , environmental science , tillage , soil carbon , soil water , manure , soil management , soil organic matter , crop rotation , agronomy , agriculture , crop , soil science , ecology , biology
Management of soil organic matter (SOM) is important for soil productivity and responsible utilization of crop residues for additional uses. CQESTR, pronounced “sequester,” a contraction of “C sequestration” (meaning C storage), is a C balance model that relates organic residue additions, crop management, and soil tillage to SOM accretion or loss. Our objective was to simulate SOM changes in agricultural soils under a range of climate and management systems using the CQESTR model. Four long‐term experiments (Champaign, IL, >100 yr; Columbia, MO, >100 yr; Lincoln, NE, 20 yr; Sidney, NE, 20 yr) in the United States under various crop rotations, tillage practices, organic amendments, and crop residue removal treatments were selected for their documented history of the long‐term effects of management practice on SOM dynamics. CQESTR successfully simulated a substantial decline in SOM with 50 yr of crop residue removal under various rotations at Columbia and Champaign. The increase in SOM following addition of manure was simulated well; however, the model underestimated SOM for a fertilized treatment at Columbia. Predicted and observed values from the four sites were significantly related ( r 2 = 0.94, n = 113, P < 0.001), with slope not significantly different from 1. Given the high correlation of simulated and observed SOM changes, CQESTR can be used as a reliable tool to predict SOM changes from management practices and offers the potential for estimating soil C storage required for C credits. It can also be an important tool to estimate the impacts of crop residue removal for bioenergy production on SOM level and soil production capacity.