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Article
Plant litter quality affects the accumulation rate, composition, and stability of mineral-associated soil organic matter
Soil Biology and Biochemistry
  • S. Carolina Cordova, Iowa State University
  • Dan C. Olk, U.S. Department of Agriculture
  • Ranae N. Dietzel, Iowa State University
  • Kevin E. Mueller, Cleveland State University
  • Sotirios V. Archontoulis, Iowa State University
  • Michael J. Castellano, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
1-1-2018
DOI
10.1016/j.soilbio.2018.07.010
Abstract

Mineral-associated organic matter (MAOM) is a relatively large and stable fraction of soil organic matter (SOM). Plant litters with high rates of mineralization (high quality litters) are hypothesized to promote the accumulation of MAOM with greater efficiency than plant litters with low rates of mineralization (low-quality litters) because litters with high rates of mineralization maximize the synthesis of microbial products and most MAOM is microbial-derived. However, the effect of litter quality on MAOM is inconsistent. We conducted four repeated short-term incubations (46-d each) of four plant litters (alfalfa, oats, maize and soybean) in two low-carbon subsoils (sandy loam and silty loam) with and without nutrient addition. Our short-term incubations focused on the initial stage of litter decompositionduring the time when litter quality has a measureable effect on mineralization rates. Plant litter quality had a much greater effect on litter-C mineralization rate and MAOM-C accumulation than did soil type or nutrient addition. Soils amended with high-quality oat and alfalfa litters had greater MAOM-C accumulation than soils amended with low-quality maize and soybean litters. However, soils amended with high-quality litters also had greater litter-C mineralization than soils amended with low-quality litters. As a result, the accumulation of MAOM-C per unit of litter-C mineralization was lower in soils amended with high-vs. low-quality litters (0.65 vs. 1.39 g MAOM-C accumulated g−1 C mineralized). Cellulose and hemicelluose indices of accumulated MAOM were greater for maize and soybean than oats and alfalfa, however, most carbohydrates in MAOM were plant-derived regardless of litter quality. At the end of the incubations, more of the accumulated MAOM-N was potentially mineralizable in soils amended with high quality litters. Nevertheless, most of the litter-C remained as residual litter; just 12% was mineralized to CO2 and 13% was transferred to MAOM. Our results demonstrate several unexpected effects of litter quality on MAOM stabilization including the direct stabilization of plant-derived carbohydrates.

Comments

This article is published Córdova, S. Carolina, Dan C. Olk, Ranae N. Dietzel, Kevin E. Mueller, Sotirios V. Archontouilis, and Michael J. Castellano. "Plant litter quality affects the accumulation rate, composition, and stability of mineral-associated soil organic matter." Soil Biology and Biochemistry 125 (2018): 115-124. 10.1016/j.soilbio.2018.07.010.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Citation Information
S. Carolina Cordova, Dan C. Olk, Ranae N. Dietzel, Kevin E. Mueller, et al.. "Plant litter quality affects the accumulation rate, composition, and stability of mineral-associated soil organic matter" Soil Biology and Biochemistry Vol. 125 (2018) p. 115 - 124
Available at: http://works.bepress.com/castellano-michael/41/