Estimating the size of the inert organic matter pool from total soil organic carbon content for use in the Rothamsted carbon model

• Published in: Soil biology & biochemistry 1998-08, Vol.30 (8), p.1207-1211
• Main Authors: Falloon, Pete, Smith, Pete, Coleman, Kevin, Marshall, Stewart
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Soil science
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/S0038-0717(97)00256-3

The Rothamsted carbon model (RothC: Jenkinson and Rayner, 1977; Coleman and Jenkinson, 1996), is one of the earliest computer-based models for the turnover of soil organic matter (SOM). In order to initialise RothC, the user specifies the inert organic matter (IOM) content of the soil, which is estimated by the model from soil radiocarbon data. However, radiocarbon measurements are expensive to obtain and so are rarely available. Regressions have been used to estimate plant inputs, hydraulic parameters and initial values for SOM models (Parton et al., 1988; Franko et al., 1995). We describe a statistical analysis of existing soil radiocarbon measurements, which suggests that soil IOM values can be roughly estimated from the total soil organic carbon (SOC) content, regardless of soil-type, land-use or climate. Our estimate provides a default value for IOM for use in RothC in the absence of radiocarbon data.