Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: NUTRIENT CYCLING AND UTILIZATION ON ORGANIC DAIRY FARMS

Location: New England Plant, Soil and Water Research Laboratory

Title: Influence of Decomposition on Chemical Properties of Plant-and Manure-Derived Dissolved Organic Matter and Sorption to Goethite

Authors
item Hunt, James - UNIV OF ME
item Ohno, Tsutomu - UNIV OF ME
item He, Zhongqi
item Honeycutt, Charles
item Dail, D Bryan - UNIV OF ME

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 10, 2006
Publication Date: January 9, 2007
Citation: Hunt, J.F., Ohno, T., He, Z., Honeycutt, C.W., Dail, D.B. 2007. Influence of Decomposition on Chemical Properties of Plant-and Manure-Derived Dissolved Organic Matter and Sorption to Goethite. Journal of Environmental Quality. 36:135-143

Interpretive Summary: 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 soil mineral component goethite of fresh and decomposed hydrophilic (HPL) and hydrophobic (HPB) DOM fractions extracted from the shoots and roots of crimson clover, corn, soybean, and hairy vetch residues, as well as dairy and poultry manures. Sorption was positively related to several DOM parameters. A ten-day laboratory decomposition of the source organic matter generally increased the sorption of the extracted DOM onto the soil mineral component goethite. This work demonstrated that microbially-driven decomposition processes resulted in greater sorption of plant and manure-derived DOM to soil solid components. This fundamental research shed light on the process affecting the DOM distribution and characteristics which would eventually increase our understanding of the organic C pool in soils.

Technical 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 of fresh and decomposed hydrophilic (HPL) and hydrophobic (HPB) DOM fractions extracted from the shoots and roots of crimson clover residue, corn residue, soybean residue, hairy vetch residue, and dairy and poultry manures. Sorption was positively related to apparent molecular weight (MWAP), abundance of aromatic groups as measured by absorptivity at 280 nm, and phenolic acid content. A ten-day laboratory 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 MWAP values of the DOM samples following sorption to goethite. In some cases the reduction in MWAP was large, indicating a strong preference by goethite for the higher MWAP DOM fractions. We conclude that microbially-driven decomposition processes can result in greater sorption of plant and manure-derived DOM to soil solids, thereby leading to increases in the soil organic C pool.

Last Modified: 7/24/2014
Footer Content Back to Top of Page