Soil C models for evaluating the effect of cover crops

Excel implementation and dataset for three C cycling models: 

• Yasso20: monthly simulation version
• SOMIC 1.0: excel implementation with both simple time step and Euler-Heng iteration
• Single pool simulation model
• In addition input files for DNDC.Can.9.5.8 for one of the farms. 

There are three versions of the SOMIC model:

1. The Zip file contains the operational version of the files for the cover crop experiment example and an 
2. _Euler-Heng version is an alternative version of the numerical simulation, which can be unstable (feel free to improve, do not use for simulation as such)
3. The _MC version is a Monte Carlo uncertainty analysis implementation for one farm. (Using Simulacion 4.0 https://ucema.edu.ar/~jvarela/index_eng.htm) 

The models are applied to an cover crop experiment, where four farms tested cover crops for 5 years. The corresponding article is submitted to Soil Use and Management. The C input estimation zip is used to translate recorded yield and cover crop NDVI data to time series of C inputs used for the models. 

• The Yasso20 model implementation is based on Yasso20 model code: https://github.com/YASSOmodel/Yasso20/tree/main
• The SOMIC model implementation is based on: https://github.com/domwoolf/somic1
• The single pool model is as described in: https://doi.org/10.1016/j.still.2021.105204
• The DNDC.Can model version can be downloaded from: https://github.com/BrianBGrant/DNDCv.CAN

All the models are capable of simulating time series of soil C development over time, as influenced by C inputs, starting SOC and soil temperature and moisture. They are presented here for the purpose of further model development and comparison, not for making accurate forecasts.