RothC is a model for the turnover of organic carbon in non-waterlogged topsoil that allows for the effects of soil type, temperature, soil moisture and plant cover on the turnover process. It uses a monthly time step to calculate total organic carbon (t ha-1), microbial biomass carbon (t ha-1) and Δ14C (from which the equivalent radiocarbon age of the soil can be calculated) on a years to centuries timescale. It requires few inputs and those it needs are easily obtainable.
RothC was originally developed and parameterized to model the turnover of organic C in arable topsoil from the Rothamsted long-term field experiments - hence the name. Later, it was extended to model turnover in grassland and in woodland and to operate in different soils and under different climates. It has now been widely tested and used at the plot, field, regional and global scales using data from many long-term experiments, different regions, and counties throughout the world.
RothC is designed to run in two modes: ‘forward’ in which known inputs are used to calculate changes in soil organic matter and ‘inverse’, when inputs are calculated from known changes in soil organic matter.
Recent developments include a version for volcanic soils, dry soils and a carbon in the subsoil version (RothPC).