Calculate the capacity of soils to supply Magnesium for the BLN production function

This function calculates an index for the availability of Magnesium in soil

Usage

bln_c_magnesium(
  B_LU_BRP,
  B_SOILTYPE_AGR,
  A_SOM_LOI,
  A_CLAY_MI,
  A_PH_CC,
  A_CEC_CO,
  A_K_CO_PO,
  A_MG_CC,
  A_K_CC
)

B_LU_BRP: (numeric) The crop code from the BRP
B_SOILTYPE_AGR: (character) The agricultural type of soil
A_SOM_LOI: (numeric) The percentage organic matter in the soil (%)
A_CLAY_MI: (numeric) The clay content of the soil (%)
A_PH_CC: (numeric) The acidity of the soil, measured in 0.01M CaCl2 (-)
A_CEC_CO: (numeric) The cation exchange capacity of the soil (mmol+ per kg), analyzed via Cobalt-hexamine extraction
A_K_CO_PO: (numeric) The occupation of the CEC with potassium (%)
A_MG_CC: (numeric) The plant available content of Mg in the soil (mg Mg per kg) extracted by 0.01M CaCl2
A_K_CC: (numeric) The plant available potassium, extracted with 0.01M CaCl2 (mg per kg),

An index representing the availability of Magnesium in a soil. A numeric value.