This tab is on the Water Balance Subregions dialog box.
If there are cells declared as FALLOW/BARE then BARE_RUNOFF_FRACTION determines the fraction of runoff to infiltration for precipitation that falls on bare soil/fallow land. A cell is considered bare if the crop ID is < 1 or if the sum of crop fractions for a cell do not sum to 1. If BARE_RUNOFF_FRACTION is not specified then it is set to 1.0 by default to disable any infiltration from precip over bare soil.
