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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #263784
Title: Development and application of a soil organic matter based soil quality index in mineralized terrane of the Western US

Author
item BLECKER, S - Us Geological Survey (USGS)
item STILLINGS, L - Us Geological Survey (USGS)
item AMACHER, M - Us Forest Service (FS)
item Ippolito, James
item DECRAPPEO, N - Us Geological Survey (USGS)

Submitted to: Environmental Earth Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2012
Publication Date: 8/12/2012
Citation: Blecker, S.W., Stillings, L.L., Amacher, M.C., Ippolito, J.A., Decrappeo, N.M. 2012. Development and application of a soil organic matter based soil quality index in mineralized terrane of the Western US. Environmental Earth Sciences. 68:1887-1901. DOI 10.1007/s12665-012-1876-8.

Interpretive Summary: We studied the relationship between soil organic matter and soil abiotic and biotic properties in three arid to semi-arid unmineralized versus mineralization terranes: serpentine, acid sulfate and Cu/Mo porphyry systems. Soil enzyme activity was a consistent explanatory variable in the models across the study sites, while microbial carbon substrate utilization rarely occurred in the models. Though similar indicators were significant in models across different mineralization types, pooling data across sites inhibited model differentiation of undisturbed and disturbed sites. The soil quality index procedure could be used to monitor recovery of disturbed systems in mineralized terrane and to help link scientific and management disciplines.

Technical Abstract: Soil quality indices provide a means of distilling large amounts of data into a single metric that evaluates the soil’s ability to carry out key ecosystem functions. Primarily developed in agroecosytems, then forested ecosystems, we set out to develop and apply an index using the relation between soil organic matter and key soil abiotic and biotic properties in more semi-arid of the Western US arid systems impacted by different geologic mineralization types. We studied these relations in three different mineralization types: serpentine, acid sulfate and Cu/Mo porphyry systems at four different sites in California and Nevada. Soil samples were collected from undisturbed soils in both mineralized and nearby unmineralized terrane as well as waste rock and tailings. We measured eight different microbial parameters (carbon substrate utilization, microbial biomass-C, mineralized-C, mineralized-N and enzyme activities of acid phosphatase, alkaline phosphatase, arylsulfatase, and fluorescein diacetate) along with a number of physicochemical parameters. We developed multiple linear regression models between these parameters and both total organic carbon and total nitrogen, and used the ratio of predicted to measured values as our soil quality index. In most instances, pooling unmineralized and mineralized soil data within a given study site resulted in lower model correlations. Enzyme activity was a consistent explanatory variable in the models across the study sites, while carbon substrate utilization rarely occurred in the models. Though similar indicators were significant in models across different mineralization types, pooling data across sites inhibited model differentiation of undisturbed and disturbed sites. This procedure could be used to monitor recovery of disturbed systems in mineralized terrane and to help link scientific and management disciplines.