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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #308656
Title: Characteristics of plant-derived water extractable organic matter and its effects on phosphorus sorption behavior

Author
item HUNT, JAMES - University Of Maine
item He, Zhongqi

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 3/18/2015
Publication Date: 10/2/2015
Citation: Hunt, J.F., He, Z. 2015. Characteristics of plant-derived water extractable organic matter and its effects on phosphorus sorption behavior. In: He, H, Wu, F., editors. Labile Organic Matter - Chemical Composition, Functions, and Significance in Soil and the Environment. SSSA Special Publication 62. Madison, WI:Soil Science Society of America. p. 99-118.

Interpretive Summary: The incorporation of crop residues into soil is an important agricultural management technique for maintaining soil quality and nutrient availability through the replenishment of C to soil ecosystems. Water-extractable organic matter (WEOM) fraction is the most labile and mobile fraction of organic matter. In this chapter, we have reviewed and discussed our work on the characterization of WEOM solutions derived from the roots and shoots of several agriculturally relevant crop plants. These plant-derived WEOM samples contain mainly lipids, protein, and lignin with some carbohydrates, unsaturated hydrocarbons and condensed aromatic compounds. Decomposition of these plant-derived WEOM samples increased their sorptivity to soil minerals. Information in this chapter is helpful in providing a better understanding of the relationship between plant-derived WEOM composition and its behavior in soil environments, and can contribute to the overall goal of better management of plant residues for agricultural sustainability.

Technical Abstract: The incorporation of crop residues into soil is an important agricultural management technique for maintaining soil quality and nutrient availability through the replenishment of C to soil ecosystems. Water-extractable organic matter (WEOM) fraction is the most labile and mobile fraction of organic matter. In this chapter, we reviewed and discussed spectroscopic and wet chemical work on the characterization, decomposition, and soil mineral P sorption effects of WEOM solutions derived from the roots and shoots of several agriculturally relevant crop plants. In contrast to their relatively minor proportion in soil, the content of WEOM in plant biomass and animal manure is high. These plant-derived WEOM samples contain mainly lipids, protein, and lignin with some carbohydrates, unsaturated hydrocarbons and condensed aromatic compounds. In general, WEOM from decomposed materials inhibited P sorption to a greater extent than did WEOM derived from fresh materials. This stronger inhibition highlights the importance of microbial processes in the release of soluble soil P. Information in this chapter is helpful in providing a better understanding of the relationship between plant-derived WEOM composition and its behavior in soil environments, and can contribute to the overall goal of better management of plant residues for agricultural sustainability.