Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: April 13, 1997
Publication Date: N/A
Technical Abstract: Potentially mineralizable carbon (PMC) is an important part of soil quality assessment, as it is an expression of soil microbial activity via soil respiration, provides clues to nutrient cycling and availability, and indicates the status of soil organic matter, which is an important factor controlling hydrological and biogeochemical processes. Measurement of PMC as an index of soil quality within a watershed should account for both management-induced and inherent spatial variability. We determined PMC at sampling intervals from <1 m to 500 m from grazed bermudagrass pastures in an effort to further our understanding of soil ecological processes at different resolutions of spatial scale. At a scale of less than 1 m, variation in PMC can be specifically attributed to differences in the quantity and quality of plant and animal detritus present. However, at larger scales, variation in PMC, in addition to gross management-induced changes in plant and animal inputs, can also be attributed to edaphic factors, such as texture, aggregation, and topography. Sampling schemes to assess soil quality within a watershed should consider the change in major controlling factors at different levels of spatial scale.