Modelling of the Soil Organic Fraction in a Limestone Deposit Within a Mediterranean Environment

This work of mathematical modelling of carbon (C) and nitrogen (N) fluxes between microorganisms and plants in pure and associated cultures of durum wheat and faba bean demonstrates the close link between the C and N cycles in agroecosystems, including differences between flows of these two elements originated from atmosphere for C and soil and atmosphere for N. Based on the parameters and functions previously defined on microbial ecology by the MOMOS model, the method provided an optimal set of new parameters of exchange between plant organs and microbes in accordance with the literature. It allows proposing agronomic solutions to improve the system studied and more generally a methodology to optimize the plant production using the ecological mechanisms. It will adjust the root demand for mineral N linked to photo-synthesized C with the microbial production of inorganic nitrogen linked to the availability of plant substrates, soil organic reserves and fixation of atmospheric N₂. This study highlights the importance of combining microbial mechanisms and plant production. The model emerges as the mathematical tool of a new ecological intensification, which additionally will improve global change prediction and mitigation.