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United States Department of Agriculture

Agricultural Research Service

Title: Impact of Soil Organisms and Organic Matter on Soil Structure

Authors
item Stott, Diane
item Kennedy, Ann
item Cambardella, Cynthia

Submitted to: Soil Quality and Soil Erosion Interactions
Publication Type: Book / Chapter
Publication Acceptance Date: September 30, 1997
Publication Date: N/A

Technical Abstract: Soil quality has moved beyond being equated solely with productivity, to inclusion of the soil's capacity to partition water and maintain environmental quality. A final determination of the soil's relative quality is dependent upon it's use. Concentrating on agricultural uses, we'll discuss the impact of the soil microbial communities on the soil quality aspect of water partitioning, to include soil crusting, infiltration rates, aggregation and compaction. Soil organic matter (SOM) influences these soil physical characteristics. A major activity is the decomposition and transformation of organic residues (plant and animal) into SOM. There is evidence that management strategies influence not only the amount of SOM in soil, but how it is distributed in various fractions: humic, fulvic or humin, light vs. heavy; or particulate vs. soluble. New research indicates that the relative distribution of SOM amongst the fractions impacts soil structure, crusting and erodibility. The nature of soil biological communities, microbial and macrofaunal, make them a sensitive indicator for assessing alterations in soil quality due to changing management practices. Soil populations may provide advanced evidence of changes in the soil before changes in soil physical and chemical properties become apparent. Methods to assess the status of the soil microbial communities are available, but interpretation is challenging. The research community is continuing to increase the understanding of the relation between assay results and status of the soil system. This leads to knowledge of how management, soil biological communities, and soil quality interact with change, thus allowing for more informed management decisions.

Last Modified: 11/25/2014