ARS | Publication request: IMPACT OF SOIL ORGANISMS AND ORGANIC MATTER ON SOIL ERODIBILITY

Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: May 31, 1996
Publication Date: N/A

Technical Abstract: Soil quality has moved beyond being equated solely with productivity, to the inclusion of the soil's capacity to partition water and maintain environmental quality. A final determination of a soil's relative quality is dependent upon its use. Concentrating on agric. uses, we will discuss the impact of the soil microbial communities on the soil quality aspect of water partitioning. This includes soil erodibility, crusting, infiltration rates, amount of runoff, aggregation and compaction. Soil organic matter greatly influences these soil physical characteristics. A major activity of the soil microbial community is the decomposition and transformation of organic residues into soil organic matter (SOM). There is evidence that management strategies influence not only the amount of SOM present in the soil, but how it is distributed in various fractions: humic, fulvic or humin; light or heavy; or particulate vs. soluble. New research indicates that the relative distribution of SOM amongst the fractions impacts soil structure, crusting and erodibility. The dynamic 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 subtle changes in the soil before changes in soil physical and chemical properties become apparent. Several methods to assess the status of the soil microbial communities are available. 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 and change, thus allowing for more informed management decisions.