I’ve attached a marked up version with comments. Note that water erosion (RUSLE2) and wind erosion (WEPS) have different criteria.



For RUSLE histosols get a kfact = 0.02. If the soil has organic layers then find the first mineral layer and use its kfactor. There is no other criteria.



For WEPS both histosols and soils with organic surface layers (OM > 15) and are deeper than 4 inches (>10) cm use the pre-created organic soil.ifc (or in the case of wepot the totalsand_r of the organic soil.ifc).



I’ve mentioned this as a note in the attached document; the organic soil.ifc is an expert created surrogate soil. It can’t be derived by SDA.



Eric

See attached document for more detail.

20160801 WQM-RSE-IET Soil Service Logic esh.docx