HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Liang, Y. Articles by Douglas, C. L. Search for Related Content PubMed Articles by Liang, Y. Articles by Douglas, C. L., Jr. Agricola Articles by Liang, Y. Articles by Douglas, C. L. Related Collections Soil Organic Matter Soil Models Other Soil Management

SOIL & WATER MANAGEMENT & CONSERVATION

CQESTR Simulation of Management Practice Effects on Long-Term Soil Organic Carbon

^a Dep. of Biological and Agricultural Engineering, Cooperative Extension Service, Univ. of Arkansas, Fayetteville, AR 72701-1201
^b USDA-ARS, Columbia Plateau Conserv. Research Center, P.O. Box. 370, Pendleton, OR 97801
^c USDA-ARS, Soil Plant Nutrient Research Center, Fort Collins, CO 80526
^d USDA-ARS, Agroecosystem Management Research Unit, Lincoln, NE 68583
^e USDA-ARS, Coastal Plains Soil, Water and Plant Res. Center, Florence, SC 29501

^* Corresponding author (hero.gollany{at}ars.usda.gov).

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 (r² = 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.

Abbreviations: CC, continuous corn • CH, chisel plow • MP, moldboard plow • NT, no-till • SOC, soil organic carbon • SOM, soil organic matter • ST, stubble mulch