LS is the slope length-gradient factor. The steeper and longer the slope, the higher is the risk for erosion. It is used to determine the relative effectiveness of soil and crop management systems in terms of preventing soil loss. The C factor is a ratio comparing the soil loss from land under a specific crop and management system to the corresponding loss from continuously fallow and tilled land. The C factor resulting from this calculation is a generalized C factor value for a specific crop that does not account for crop rotations or climate and annual rainfall distribution for the different agricultural regions of the country.
P is the support practice factor.
It reflects the effects of practices that will reduce the amount and rate of the water runoff and thus reduce the amount of erosion. The P factor represents the ratio of soil loss by a support practice to that of straight-row farming up and down the slope. If there is more than one soil type in a field and the soil textures are not very different, then use the soil type that represents the majority of the field. Repeat for other soil types as necessary. Divide the field into sections of uniform slope gradient and length.