High temperatures, compounded by climate change, may affect crops
High temperatures are forecast across Pennsylvania as parts of the country, including the Southwest, grapple with sweltering heat. Experts say that with sufficient moisture, farmers in Butler County can expect a minimal impact on crops, but should keep an eye on livestock, which are prone to heat stress.
With adequate soil moisture, a few days of high heat around 90 degrees Fahrenheit would not be too worrisome for farmers, said JohnMark Miller, agronomist with Penn State Extension.
“Temperatures over 100 (degrees Fahrenheit) and overnight lows in the 80s would be concerning … with good soil moisture there should be a relatively minimal yield hit,” Miller said.
The primary risk is to yield, and corn and soybeans are the most likely to be vulnerable, Miller said. Corn decreases its growing rate at around 95 degrees, and at above 85 degrees, soybeans may experience issues with seed production, said Miller.
“With moisture at improper timings, corn sets less kernels, soybeans form less pods, and small grains put out smaller grain,” Miller said. “Forage crops will also be slower to grow and therefore drop yield.”
Friday, July 28, may be one of the hottest days of the summer in Butler County, said meteorologist Chris Leonardi of the National Weather Service’s Pittsburgh office.
The heat can be partly attributed to El Nino, a large-scale, cyclical weather event, he said. While hot weather can’t be solely attributed to a singular, specific event, Leonardi said climate change would make heat waves more likely over time.
Climate change can exacerbate existing natural processes, with El Nino being one of them, said Kristina Dahl, principal climate scientist with the Union of Concerned Scientists.
While warm weather is natural and expected during the summer, Dahl said that climate change can drive high temperatures even higher.
“Climate change plays a very clear role in driving temperatures higher because as we are warming the planet, on average it is easier and easier for heat waves to reach extreme temperatures,” said Dahl. “Climate scientists have been able to determine (that) without human cause, heat waves would have been virtually impossible.”
Dahl said that climate scientists are also researching how climate change impacts the pattern of jet streams, or air currents, that run West to East and propel weather systems eastward. Some climate research suggests that climate change contributes to “bigger oscillations,” Dahl said, enabling weather patterns to get trapped like the persistent heat wave in the Southwest.
“We have seen an increase in frequency and intensity of extreme heat in the United States, a lengthening of warm seasons, spring starting earlier, fall arriving later,” she said.
The humidity, though good for crops that require moisture to thrive in high temperatures, also magnifies the heat. High humidity makes sweating less efficient, hindering the body’s ability to cool down.
For farmers, the stifling heat also means taking measures to protect their animals.
“It’s going to be stressful for livestock,” said Ken Metrick, farmer and owner of the family-run Metrick’s Harvest View Farm and Market.
Metrick said farmers should prepare to regularly check on their livestock, provide them with plenty of water and keep animals, such as cows, in well-ventilated barns during the hottest hours.
“We always provide them with shade and clean, fresh water,” Metrick said. “Dairy people, they’ll keep their cows in the barn in the daytime.”
Dry weather earlier this summer hindered the growth of some crops, Metrick said, including sweet corn, hay and soy.
Metrick expressed that he is not concerned about the impact of high temperatures on his crops as long as there is sufficient moisture, and the heat is not accompanied by dry weather.
Metrick said that he would begin to worry if irregular weather events continued.
“I remember summers 40 years ago like this as a kid,” he said. “A few more years, maybe we’ll see a bigger difference.”
Heat Safety Guidelines
According to the Pennsylvania Emergency Management Agency, high temperatures can be dangerous for children and older adults, those working outdoors, and people in urban areas.
Awareness of heat-related illnesses, which range in severity from heat cramps to heat stroke, can help in preventing and recognizing heat related sickness.
Pets and livestock are also at risk of developing heat stress, said PEMA Director Randy Padfield.
In a news release, Agriculture Secretary Russell Redding made additional recommendations to keep pets and livestock safe:
Provide shade: Move animals to shaded areas if possible.
Provide water: As temperatures rise, animals need to consume more water.
Provide fans: Air movement can help lower humidity in areas where animals gather for quicker, more effective cooling.
Avoid overworking livestock: It’s safest to work with livestock early in the morning when their body temperatures are lower. Postpone routine health management such as nail or hoof trimming that might add stress until the weather cools.
Avoid unnecessary transportation: If livestock must be moved, do so in the late evening or early morning hours.
Walk dogs in early morning or late evening, when temperatures are cooler.
