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United States Department of Agriculture

Agricultural Research Service

Research Project: SOIL CONSERVATION SYSTEMS FOR SUSTAINABILITY OF PACIFIC NORTHWEST AGRICULTURE Title: Cqestr Simulations of Soil Organic Carbon Dynamics

Authors
item Gollany, Hero
item Follett, Ronald
item Liang, Yi -

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: August 8, 2011
Publication Date: June 20, 2012
Citation: Gollany, H.T., Follett, R.F., Liang, Y. 2012. CQESTR Simulations of soil organic carbon dynamics. In: Liebig, M.A., Franzluebbers, A.J., Follett, R.F., editors. Managing agricultural greenhouse gases:coordinated agricultural research through GRACEnet to address our changing climate. San Diego, CA: Academic Press. p.271-292.

Interpretive Summary: A processed-based carbon balance model, CQESTR (sequester), was used to predict soil organic carbon (SOC) dynamics and examine the effect of agricultural management practices on soil organic carbon accretion in three diverse regions of the USA. The three regions chosen had long-term experiments ranging from 23 to 134 years in duration and included: (1) Western Region, (2) Central Region, and (3) Eastern Region. The range of management practices included crop residue harvest, burning or residue retention, tillage type, fertilizer or manure addition, fallow and crop intensification, monoculture and complex crop rotation. The CQESTR model captured temporal and spatial changes in soil organic carbon. Simulation results indicated cultivation and crop residue removal decreased soil organic carbon; however, with appropriate management such as the use of conservation tillage, organic amendments, and/or cropping intensification, soil organic carbon losses could be reversed. Using fertilizer alone is insufficient to overcome crop residue removal effects on soil organic carbon. Model validation and future predictions concerning soil organic carbon management can only be conducted using a long-term (> 25 years) soil organic carbon database, because stable soil organic carbon changes occur very slowly.

Technical Abstract: A processed-based carbon (C) model, CQESTR (sequester), was used to predict soil organic carbon (SOC) dynamics and examine the effect of agricultural management practices on SOC accretion in three diverse regions of the USA. The three regions chosen had long-term experiments (LTEs) ranging from 23 to 134-yr in duration and included: (1) Western Region, (2) Central Region, and (3) Eastern Region. The range of management practices included crop residue harvest, burning or residue retention, tillage type, fertilizer or manure addition, fallow and crop intensification, monoculture and complex crop rotation. The CQESTR model captured temporal and spatial changes in SOC. Simulation results indicated cultivation and crop residue removal decreased SOC; however, with appropriate management such as the use of conservation tillage, organic amendments, and/or cropping intensification, SOC losses could be reversed. Using fertilizer alone is insufficient to overcome residue removal effects on SOC. Model validation and future predictions concerning SOC management can only be conducted using a long-term (> 25 yr) SOC database, because stable SOC changes occur very slowly and requires several decades to reach equilibrium.[GRACEnet Publication]

Last Modified: 10/20/2014
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