Sudden droughts are also a global problem, with Brazil, India and several African countries facing the worst impacts. In 2010, a rapid drought followed by a heat wave in Russia temporarily halted wheat exports, a major disruption to grain-dependent communities across the Middle East.
The damage that rapid droughts can cause depends on the harvest and the time of year, said Dennis Todey, director of the Midwest Climate Center at the U.S. Department of Agriculture. Corn is most vulnerable during its mid-summer pollination season, while soybeans are affected in August and wheat during the spring planting season.
Drought is a natural part of the region’s climate, Todey said, especially in the western part of the Corn Belt, a region that spans the Midwest and the Great Plains. Many farmers have learned to adapt and integrate dry conditions into their planting cycles. But what makes rapid droughts so dangerous is their rapid onset, said Todey, who leaves little time for farmers to prepare.
“Drought is most often considered a slow start event and then a slow stop event,” Todey said. “In a fast-drying environment … instead of starting to dry out gradually, you have surfaces that dry out very quickly; you have some freshly planted crops that start to get stressed faster.”
Many farmers do not know if they are beginning to suffer from a drought, however, until the expected rains appear. The mid-October rains helped alleviate the rapid drought that began in Oklahoma in September, but then began a much longer drought, said Keeff Felty, a fourth-generation wheat and cotton farmer in the area. southwest of the state. As a result, part of their harvest never germinated, while their overall yield declined when it came time to harvest.
“There’s a lot of information out there, and you have to take advantage of what works best for you, but you also have to be prepared for it to go totally south,” Felty said. “No one saw it [the drought] coming, and it is only a fact of time that we have no control over it. It’s just life. ”
Typical droughts can last months or even years, with the western United States experiencing its third decade of “mega-drought,” while rapid droughts can end more quickly, in weeks or months, Yang said. And they can affect relatively humid areas, including the eastern part of the country, where drought conditions are much rarer than in the west.
The main reason they occur faster, Yang said, is climate change. As the air heats up, it can cause more evaporation and dry the floor. This can happen even in areas that expect more rainfall in general due to climate change, because scientists project that rainfall will be unevenly distributed, falling into more extreme events and causing other parts of the year to be drier.
“Each [recent] The decade we’ve seen is the warmest in history, “Yang said. expects both rapid and longer droughts to occur more frequently.
Researchers are working to improve their models to better predict sudden droughts, Yang said, with the help of new technologies such as more granular satellite monitoring and machine learning. The main marker they look for is high evapotranspiration rates, when plants suck water from the soil and then release it into the air through their leaves, a process that is accelerated by high temperatures and winds and which can be monitored with special cameras that detect fluorescence. , or the heat emitted by plants.
If farmers can know when to anticipate a rapid drought, Todey said, they can skip or delay planting, or reduce their fertilizer use when they know a crop will not grow. They can also adjust their planting schedule and take better care of the soil by minimizing the crop, which dries it out even more. But with less and less time to prepare for sudden droughts, Todey said, some may have to make difficult decisions about whether to plant.
“Agricultural producers naturally adapt to changing conditions,” Todey said. “It simply came to our notice then [losses] they become more frequent. People start saying, “Okay, that doesn’t work.”