Increasing water scarcity has resulted in more agricultural fields being left unplanted in California. The fallowed farmlands are now the state’s top source of human-caused dust. New research shows they account for 88% of anthropogenic dust events, especially in the Central Valley. Dust storms from these areas threaten public health, road safety, and long-term water security. Satellite data and agricultural records reveal a clear pattern. Between 2008 and 2022, both fallowed farmland and dust levels rose sharply.
Dust from fallowed farmland spreads far beyond the fields. It worsens air quality and speeds snowmelt in the Sierra Nevada mountains, reducing water availability. [For more information about the impacts of dust on snow, see our blog post here.]
Idle fields are hotter than on farmed lands. and residual heat increases the surrounding crops’ water needs, undermining the water conservation benefit of not producing on these lands. Using low-water-use cover crops can reduce dust without sacrificing groundwater savings.
Addressing this dust issue is essential for protecting both environmental and public health. Solutions must balance water conservation with land cover strategies that keep soil stable. As climate pressures mount, managing fallowed land wisely will be critical for the future of California farming.
