Soils at or below the threshold values are prone to structural destabilization, erosion, and low productivity; so the scoring value is 0.
bSoils at or beyond this values no further increase in productivity or decrease in erosion rate are achieved the upper threshold; values at and above this level thus receive a score of 1.0.
cValues receive a score of 0.5 and are generally regarded as the minimum target values.
dThe value is given a score of 1.0 if the desired relationship is bell-shaped.
eAccording to Kay and Angers [42], irrespective of soil type if SOC contents are below 1%, it may not be possible to obtain potential yields. L: lower; U: upper; SAS: soil aggregate stability; BD: bulk density; MWC: maximum water holding capacity; OC: organic carbon; CEC: cation exchangeable capacity; TN: total nitrogen; TP: total phosphorous; Pav: available phosphorous; Zn: available Zinc; Fe: available iron; —: implies not applicable.