Add optional functionality of different tillage practices #36
Description
Currently there is option to consider tillage practices in the calculations. A placeholder function is introduced in the ghsolver branch, where M_TILLAGE_SYSTEM can be given as user input yet who is not accounted for. This should be added in the form of a rate modification factor d in rc_input_rmf. Users are free to adapt this section of the code, but a first instance could potentially be made based on the work of Hyun et al., 2024:
They separate the K values based on sand content higher than 37.6%, with a subdivision in SOC content above 75.7 ton C/ha (TN1) and below 75.7 ton C /ha (TN2), and sand content lower than 37.6%, with a subdivision of sand content higher than 35% (TN3) and below 35% (TN4). K values of each split for the different pools are as follows:
