Is adding charcoal to soil a good method for CO2 sequestration? : modeling a spatially homogeneous soil

We propose a simple mathematical model (a coupled system of nonlinear ODEs) able to capture dynamical effects produced by adding charcoal to fertile soils. Our main aim is to understand to which extent charcoal (in its biochar form) is able to lock up carbon in soils. Our results are preliminary in the sense that we do not actually solve the CO2 sequestration problem, but we do set up a modeling framework in which this can be tackled by means of mathematical tools. We show that our model is well-posed and has interesting steady states. Depending on the reference parameter range and chosen time scale, numerical simulations suggest that adding charcoal postpones the release of CO2 for a large variety of soils.