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Influence of Decomposition on Chemical Properties of Plant‐ and Manure‐Derived Dissolved Organic Matter and Sorption to Goethite
Author(s) -
Hunt James F.,
Ohno Tsutomu,
He Zhongqi,
Honeycutt C. Wayne,
Dail D. Bryan
Publication year - 2007
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2006.0133
Subject(s) - sorption , dissolved organic carbon , chemistry , goethite , environmental chemistry , organic matter , decomposition , manure , agronomy , adsorption , organic chemistry , biology
ABSTRACT Sorption of dissolved organic matter (DOM) plays an important role in maintaining the fertility and quality of soils in agricultural ecosystems. Few studies have examined the effects of decomposition on DOM sorption and chemical characteristics. This study investigated the sorption to goethite (α‐FeOOH) of fresh and decomposed hydrophilic (HPL) and hydrophobic (HPB) DOM fractions extracted from the shoots and roots of crimson clover ( Trifolium incarnatum L.), corn ( Zea mays L.), soybean [ Glycine max (L.) Merr.], hairy vetch ( Vicia villosa L.), and dairy and poultry manures. Sorption was positively related to apparent molecular weight (MW AP ), aromaticity as measured by absorptivity at 280 nm, and phenolic acid content. A 10‐d laboratory microbial decomposition of the source organic matter generally increased the sorption of the extracted DOM onto goethite. The decomposition effect on sorption was greater for the HPL fractions than for the HPB fractions. There was a decrease in the MW AP values of the DOM samples following sorption to goethite. In many cases the reduction in MW AP was large, indicating a strong preference by goethite for the higher MW AP DOM fractions. The results of this laboratory‐based research demonstrate that microbial processes affect the chemical characteristics of DOM which may affect the distribution of soil organic C pools.