Carbon mineralization kinetics as influenced by soil properties
1996
Riffaldi, R. | Saviozzi, A. | Levi-Minzi, R.
In a short-term laboratory study C mineralization potentials were determined on soil samples obtained from some representative agricultural soils in Tuscany, Italy. All the kinetic models tested to describe the mineralization process provided a good fit to the experimental data. A modified first-order model best described C mineralization in the soil. Both potentially mineralizable C and the mineralization rate varied considerably among soils, reflecting the differences in soil properties. Potentially mineralizable C was positively related to C evolved as CO2 and to the exchange capacity. Normalized values (potentially mineralizable C divided by organic C), representing on average about 2% of the total soil C, was positively correlated to soil pH and negatively to the soil C pool, the soil N pool, and total microbial activity. Values for mineralization rate ranged between 0.050 and 0.104 day-1, being higher in fine-textured soils and in soils with a large free Fe content. A low C:N ratio was indicative of a high mineralization rate value. Turnover times for mineralized C were relatively rapid, ranging from 10 to 20 days.
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