An analytical model of soil organic carbon dynamics based on a simple'hockey stick' function

摘要

We developed a simple analytical model for carbon and nitrogen dynamics in soils. Description of the soil C and N dynamics focus on the total carbon residue function, R, defined as the fraction of original plant carbon input remaining in the soil as a function of time, and nitrogen concentration function, N, defined as the N concentration of the carbon residue as a function of R. A simple two-parameter function, R = Exp(-(kt)(alpha)), was used for total carbon residue function. N concentration of carbon residue is derived to be a linear function of R. We tested our model with data reported in the literature. The model parameters (k and alpha) were calculated from independently determined gross turnover time and C-14 age of soil organic carbon. Our model accurately predicts C and N dynamics in response to fertilization and manure application for time periods ranging from a few months to more than 150 years.