Flash droughts are also a global problem, with Brazil, India and many countries in Africa faces the worst effects. In 2010, a sudden drought followed by a heat wave in Russia temporarily halted wheat exportsa major disruption to communities across the Middle East that depend on the country's grain.
The damage that sudden drought can cause depends on the crop and the time of year, said Dennis Todei, director of the Midwest Climate Hub for the U.S. Department of Agriculture. Corn is most vulnerable during its mid-summer pollination season, while soybeans are affected in August and wheat at spring planting.
Drought is a natural part of the climate in this region, Todey said, particularly in the western part of the Corn Belt — an area that includes the Midwest and Great Plains. Many farmers have learned to adapt and integrate dry conditions into their planting cycles. But what makes droughts suddenly so dangerous is their rapid onset, Todey said, leaving little time for agricultural producers to prepare.
“Drought is often thought of as a slow-start, slow-stop event,” Todey said. “In an extreme drought environment … instead of starting to dry gradually, you have surfaces that dry very quickly. you have some newly planted crops that start to stress more quickly.”
Many farmers don't know if they're starting to experience drought, however, until the expected rains don't show up. Rains in mid-October helped alleviate the sudden drought that began in Oklahoma in September, but it was followed by a much longer drought, said Keeff Felty, a fourth-generation wheat and cotton farmer in the southwestern part of the state. As a result, some of his crop never germinated, while his overall yield dropped 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 completely south,” Felty said. “No one saw [the drought] it's coming, and it's just a fact of the weather that we have no control over. It's just life.”
Typical droughts can last months or even years – the western US is currently in its third decade of “great drought”—while sudden droughts can end more quickly, within weeks or months, Yang said. And they can hit relatively wet areas, including the eastern part of the country, where drought conditions are much rarer than in the West.
The main reason they're happening faster, Yang said, is climate change. As the air warms, it can lead to more evaporation and dry out the soil. This can happen even in areas that are expected to receive more rainfall overall due to climate change, because scientists predict that rainfall will be unevenly distributed – falling in more extreme events and making other parts of the year drier.
“Each [recent] The decade we've seen is the warmest decade on record,” Yang said. And with the world in orbit to overcome a global temperature that is 1.5 degrees Celsius (2.7 degrees Fahrenheit) higher than the pre-industrial average, he expects to see both upcoming droughts and longer droughts occur more frequently.
Researchers are working to improve their models to better predict droughts, Yang said, with the help of new technologies such as more detailed satellite tracking and machine learning. The main indicator they look for is high rates of evapotranspiration, when plants absorb 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 can be monitored with special cameras that detect fluorescence , or the heat emitted by plants.
If farmers can know when to expect a sudden drought, Todey said, they can skip or delay planting or reduce fertilizer use when they know a crop won't grow. They can also adjust their planting schedule and take better care of their soil by minimizing tillage, which dries it out even more. But with less and less time to prepare for drought, Todey said, some may have to make tough choices about whether to plant at all.
“Agricultural producers naturally adapt to changing conditions,” Todey said. “But eventually there comes a point where [losses] are becoming more frequent. People are starting to say, “Okay, this isn't working.”
