Campus Units

Agronomy

Document Type

Article

Publication Version

Published Version

Publication Date

2-6-2014

Journal or Book Title

European Journal of Soil Biology

Volume

61

First Page

68

Last Page

71

DOI

10.1016/j.ejsobi.2014.01.003

Abstract

The role of abiotic processes on dissolved organic matter (DOM) production is often underappreciated. However, abiotic processes appear to be especially important in subsoils where, with increasing depth, microbial activity declines and soil organic matter (SOM) becomes a progressively more important contributor to DOM. Within three soil depths (20, 40, and 60 cm) in a temperate forest, soil temperature was positively associated with dissolved organic carbon (DOC) concentration (R2 = 0.23–0.77) and the DOM humification index (R2 = 0.35–0.72) for soil solutions in slow and fast flowpaths. With increasing soil temperature from 5 to 24 °C, average DOC concentrations increased by 86% at 20 cm, 12% at 40 cm and 12% at 60 cm soil depths. Our data suggest that DOM supply, especially in subsoils, is temperature dependent. We attribute this to the influence of temperature on DOM replenishment through direct processes such as SOM dissolution, diffusion and exchange reactions as well as indirect processes such as rhizodeposition and exoenzyme activity. In contrast, negative relationships (R2 = 0.71–0.88) between temperature and nitrate concentrations in subsoil suggested that the temperature-dependent supply of DOM drives microbial processes such as dissimilatory and assimilatory nitrate consumption.

Comments

This article is published as Toosi ER, Schmidt JP, Castellano MJ. 2014. Soil temperature is positively associated with dissolved organic carbon supply and negatively associated with soil solution nitrate. European Journal of Soil Biology doi: 10.1016/j.ejsobi.2014.01.003. Posted with permission.

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

Included in

Agriculture Commons

Share

COinS