How to calculate or confirm these parameters of the *.soil files?

[githublijian]

SOPE: maximum percolation rate root zone.
KSUB: maximum percolation rate subsoil.

SurfaceConductivity: Hydraulic conductivity of the surface.

[ajwdewit]

Actually these are hard to estimate. In fact, I do not know how they were derived because these files were created before I started maintaining WOFOST. This is one of the reasons we have a new waterbalance in PCSE 6/WOFOST 8.1.

If you have a pF curve for hydraulic conductivity, then your best estimate is to use the conductivity at pF=2.0 (field capacity). Otherwise, use the pF curves for the soils in the WOFOST distribution, determine the most appropriate file for your soil and determine the conductivities from the pF curves in those files.

with best regards,

Allard