Phygrow 1.2 History

Phygrow 1.2 worked within the framework of the 1.0 release, and introduced some new concepts. In the hydrologic simulation, matrix flow was added, along with an infiltration limit (so that saturated soils did not let more water in than could be drained off by the layer below.) In the plant growth simulation, the basic growth formula from WEPP that uses LAI replaced the EPIC formula that uses TRANCO and CROPCO, and turnover as a function of percent standing crop.

Phygrow 1.2 added an Extended Hydrology Report, and replaced the graphs from version 1.0 with Biomass Delta Graph, Standing Crop Graph, Growth Graph, Turnover Graph, and Cumulative Growth Graph.

The turnover function allowed direct comparision with model standing crop values against clipping data (where previously the model had reported accumulated production to date.) With the introduction of the LAI based formula, it was possible to tune the parameters to match the clipping data for the irrigated plots of little bluestem from 1991 through 1993. The sites that had co-dominant species with dissimilar growth forms (e.g. Brownseed and Woody Forbs) still did not preform well.