Can someone clarify how Field Capacity in the Zones settings is being calculated.
As I understand from the referenced link on the support pages (#1), max avail soil water (aka Field Capacity) = root depth * avail soil water per foot of the soil type. While different research documents indicate different avail water per foot, ranging anywhere from 1.2”/ft – 1.6”/ft, it seems this should be treated as a constant.
However, the online RM documentation indicates Clay having a FC of 0.54”/ft, the reference link (#1) indicates FC of both 1.6”/ft and a range of 1.2” – 1.5”/ft, and most confusing, changing the Vegetation Type on the Zones setting results in different FC factors of soil water/ft for a constant of clay soil. See table below. Even though root depth changes which changes the max Field Capacity, I would have expected the avail soil water per foot of clay to remain constant. Notice in the table it changes from 1.39 to 1.98, but I kept Clay soil type constant.
Am I missing something?
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