Criteria and indicators of forest soils used for slash-and-burn agriculture and alternative land uses in Indonesia

This chapter focuses on the initial results of the Alternatives to Slash and Bum project in Indonesia for a review of measurable indicators and historic data. It discusses the C-saturation deficit and C_org fractionation as two approaches to make changes in soil organic matter (SOM) more readily quantifiable. For both of these indicators, the chapter presents a scientific rationale, a suggested protocol for assessment and reviews the data available for interpreting results. Forest soils may lose a considerable part of their SOM content after changes in management or conversion to other land use. Models of SOM, such as the CENTURY model assume a number of pools of different turnover rates, but the measurement of such pools is an area of active research and method improvement. The Ludox fractionation method gives more sensitive indicators for studying C dynamics than total soil C_org, especially for the 0- to 5-cm depth.