Simulating soil organic carbon changes across toposequences under dryland agriculture using CQESTR

Hero T. Gollany and Abdelhamid A. Elnaggar

Ecological Modelling, 2017, vol. 355, issue C, 97-104

Abstract: Soil organic carbon (SOC) and its management under dryland cropping systems are very critical for both crop productivity and environment health. The objective of this study was to evaluate the performance of CQESTR, a process-based C model, in simulating SOC changes across toposequences of selected fields and agriculture management practices along a precipitation gradient in a dryland region of Oregon, USA. Geo-referenced soil samples were collected from summit (SU), shoulder (SH), backslope (BS), footslope (FS), and toeslope (TS) positions during early 1980s and early 2000s. Simulation scenarios were developed based on field management practices, crop rotations, soil properties, and climatic data. CQESTR simulated results were compared with the measured SOC from each landscape position. Significant (P<0.0001) correlations (r=0.93) were found between the measured and the simulated SOC at SU, SH (r=0.91), BS (r=0.83), FS (r=0.89), and TS (r=0.89). The smallest correlation value at BS could be from soil deposition due to erosion. No significant changes in SOC were found between SU, SH, BS, and FS landscape positions; however, TS had the highest SOC (10.8±.8gCkg−1). CQESTR successfully simulated SOC at most of the studied sites and landscape positions, except at TS for a location with high annual deposition of C-rich soil eroded from the upper landscape position. CQESTR could be used to predict SOC changes across toposequence and at the landscape scale level with reasonable accuracy. The results were supported by a linear relation with an r2 of 0.89 and a low mean square deviation (MSD=0.24) between the measured and the simulated SOC.

Keywords: Carbon model; Carbon accretion; Carbon sequestration; Crop rotation; Landscape positions; Soil organic matter; Tillage (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0304380016305130
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:ecomod:v:355:y:2017:i:c:p:97-104

DOI: 10.1016/j.ecolmodel.2017.03.024

Access Statistics for this article

Ecological Modelling is currently edited by Brian D. Fath

More articles in Ecological Modelling from Elsevier
Bibliographic data for series maintained by Catherine Liu ().