Thursday March 14, 2024
Courthouse News Service —
California’s notorious droughts are a major concern for farming communities and water policymakers, but a new study emphasizes that it’s not just precipitation rates taking a toll on the agricultural water balance: Crop water demand is exacting an “invisible water surcharge” that explains half of the cumulative deficits of that water supply since 1980.
The amount of water a plant needs is determined by the rate of its evapotranspiration, which is the combination of evaporation from soil and plant surfaces and water absorbed by plant roots that is released through the leaves as a vapor.
As temperatures increase due to climate change, the atmosphere can hold more moisture creating a vapor pressure difference that can draw moisture from plant and soil surfaces.
These climate-induced changes to evapotranspiration are playing an increasing role in the growing water deficit in San Joaquin Valley, according to a new study published Wednesday in the Public Library of Science Water journal.