AMG_base

AMG_base is a R version of the AMGv2 model (Clivot et al., 2019: https://doi.org/10.1016/j.envsoft.2019.04.004). It is a simple model simulating topsoil organic carbon (SOC) stocks in arable cropping systems, at an annual time step.

This R code gives identical results than the C++ version "AMG_recherche". However, it is a basic version because it does not include the calculation of C3 and C4 stocks, optimisation procedure, or graphical representation.

Directories

• inputs includes the input files
• scripts includes the R code
• outputs includes the output files produced by the R code

Model description

The full model description is available in the original publication of Clivot et al. (2019) at https://doi.org/10.1016/j.envsoft.2019.04.004 or https://hal.science/hal-02161566.

The input parameters included in the csv files parameters_EOM, parameters_MINERALIZATION and parameters_PLANT (inputs directory) are also available at https://doi.org/10.57745/MEQQIX. They are provided by the AMG Consortium.

Requirements

This R script has been written and tested for R versions ≥ 4.0.0.

It requires the following packages: readr, dplyr, tidyr and stringr.

Usage

The model can be run using the R file AMG_script in the scripts directory:

• All the inputs and the parameter files (.csv files) must be located in the inputs directory.
• The user must first fill in the csv files inputs_MANAGEMENT, inputs_METEO and inputs_SOIL to discribe the simulated cropping system(s) (an example is provided).
• The structure and the names of the input and parameter files should not be changed. Do not add columns with the same names as the existing ones.
• The output files (outputs_C_SUPPLY and outputs_SOC_STOCKS) are saved in the outputs directory.
• Input and output variable definitions, types and units are available in the csv file AMG_base_variable_list.

Citation

• Code: see https://hal.science/hal-04553490
• Parameters: see https://doi.org/10.57745/MEQQIX

Contact

Fabien Ferchaud [email protected]