New research finds that irrigated farms within Wisconsin’s vegetable-growing Central Sands region significantly cool the local climate compared to nearby rain-fed farms or forests.
Irrigation dropped maximum temperatures by one to three degrees Fahrenheit on average while increasing minimum temperatures up to four degrees compared to unirrigated farms or forests. In all, irrigated farms experienced a three- to seven-degree smaller range in daily temperatures compared to other land uses. These effects persisted throughout the year.
The results show that the conversion of land to irrigated agriculture can have a significant effect on the regional climate, which in turn can affect plant growth, pest pressure and human health in ways that could be overlooked unless land uses are accounted for in forecasts and planning.
Such a cooling effect mitigates — and obscures — a global warming trend induced by the accumulation of greenhouses gases in the atmosphere. Irrigated farming, like all agriculture, also generates greenhouses gases.
Read more at University of Wisconsin-Madison
An irrigation system waters corn plants growing in a Wisconsin farm field. (Photo Credit: JEFF MILLER)