Scientists with the U.S. Department of Agriculture (USDA) are investigating the effects of a sudden extreme rainfall event, or "deluge," on an area experiencing long-term drought, to help the nation's farmers better navigate climate change.
Agricultural Research Service scientists in Ft. Collins, Colo., are examining the impacts of a deluge during a drought on forage crop production and the intake and release of carbon, also called carbon cycling on semi-arid grassland in the eastern part of the state, by using rain shelters to recreate drought conditions, the USDA announced Jan. 25.
"Producers across the country face the increasing threats of multiple climate extremes," USDA states in the announcement, "which when combined, often have economic and ecological impacts worse than the same extremes in isolation.
The USDA states extended droughts in western states are forcing producers to change their agricultural practices to mitigate crop losses. The difficulties of farming in a drought-prone region are increased by the increasing frequency and intensity of deluges, the USDA reports.
The deluges caught the scientists' attention, according to Research Ecologist and Ecohydrologist David Hoover.
"While working on shortgrass, we noticed a lot of research on drought and rainfall in the Western states, but not enough on deluges," Hoover said in the announcement, "which is one of the key predictions with climate change — more extreme rainfall events are expected to happen, and could even happen during a drought."
Researchers measured the effect of a sudden deluge during an extended drought on end-of-season production and carbon cycling, During drought, carbon uptake in the soil is reduced, plants deteriorate early and there is a marked decline in production, the USDA reports.
"When a deluge was added during drought, rapid changes were observed, including regreening of brown vegetation and a large pulse in carbon uptake within days," Hoover said in the report.
Hoover said the positive effects of a single deluge during an extended drought only lasted about a month, meaning one deluge provides partial and short-lived compensation.
USDA reports Hoover and a team of scientists at Colorado State University will continue to study how weather extremes impact crop production and livestock, at larger scales and over longer periods of time, the announcement states.
The study was funded by USDA, National Institute of Food and Agriculture.
