Monsoons might be pouring water over eastern Arizona, but persistent drought conditions and heat are still having an affect on local crops and cattle.
Like humans, other mammals, like cattle, can exhibit behaviors like loss of appetite, loss of body weight, panting, sluggishness, difficulty breathing and even death if a cow’s body temperature starts to climb above approximately 102.5 degrees Fahrenheit because of exposure to hot temperatures and a lack of water, according to a study done by the University of Minnesota Extension in 2020.
Unlike humans though, the body temperatures of cows start to rise at much lower temperatures. A cow’s body temperature can start to experience the beginning stages of heat stress at 72 degrees Fahrenheit with 50% humidity.
“Because these animals are exposed to the environment, we want to take a look at them and take care of them,” said Joslyn Beard, livestock extension specialist at the University of Arizona.
Like people, cows are adaptable.
Beard said that although cows can start to experience heat stress at mild temperatures, cows that are born and raised in Arizona, and cows whose parents were born and raised in Arizona, have higher thresholds for heat than other cows, making them less susceptible to the worst affects of heat stress.
“Adaptation is a moving threshold,” Beard said, “cattle who are in Arizona are used to heat.”
To combat heat stress in cattle, ranchers and dairy farmers will usually vaccinate their cows against a variety of respiratory issues that start to affect cows who experience heat stress. Beard is working on a nationwide study to see if supplements put into cow feed can help combat heat stress.
But something that can’t be solved with a supplement or vaccinated against is a lack of water and that, too, plays into heat stress.
“June and July are my least favorite months,” said Calvert Allred, a rancher in Graham County. Allred said that even with the recent monsoon rains, because of the years long, lingering drought, natural vegetation for his cows to eat on is severely lacking on the land he uses to graze them on. Using well water, Allred said he has enough water for his cattle to drink, but the lack of vegetation because of the drought, compounded with the high heat of the summer exacerbates the problem of heat stress.
“That’s our downfall,” Allred said.
Crops
“There’s no doubt we’ve seen an increase in temperatures. Our summers are warmer and longer,” said Randy Norton, the director of the Graham County Cooperative Extension of the University of Arizona and the resident director of the Safford Agricultural Center. “It can affect plants for sure.”
Like mammals, crops too can experience heat stress, which can cause wilting, a lack of sterility in a crop’s pollen and even death when a plant’s internal temperature raises above 86 degrees Fahrenheit because of consistent direct sunlight or a lack of water.
A crop’s internal temperature often times can be 30 degrees cooler then its surrounding air temperature, Norton said.
Consistent direct sunlight causing a crop’s internal temperature to rise to dangerous levels is more of a problem in Maricopa County, Norton said, but in Graham and Greenlee counties, the lack of available water, coupled with the high heats of summer, can lead to problems with crops experiencing heat stress.
“Talking water in Graham County is... I don’t know. We don’t have any control over it... we do what we can to save the resource,” said Justin Leyton, a cotton farmer in Thatcher.
Leyton said his cotton can look heat stressed soon after irrigating them because of lack of access to water.
The water he can use, Leyton said, is river water full of sediment buildup from years of drought and brought up by the recent monsoon rains. That water, Leyton said, isn’t as efficient and properly irrigating his cotton crops as river water from snowmelt. As a result, cotton crops aren’t flowering properly.
“Before it started raining two weeks ago my whole garden was in danger,” said Steve Ahmann, a hobbyist farmer in Clifton, “It was too hot for them,” he said about his summer squash particularly. But although he welcomed the rain, Ahmann said it was too little too late to save a lot of the various crops he grows.
With a childhood spent farming and an academic and working background as a biologist and chemist, Ahmann moved to Clifton in 1997 and has been farming for both himself, his family, friends and occasionally for local farmers markets for over 10 years.
Growing everything from Asian eggplants, to blueberries, tomatoes, white peaches, Swiss chard, and many more crops, Ahmann said he experiences heat stress both because of the heat and from lack of water.
Where larger agro businesses rely on satellite technology to detect heat stress in crop, Ahmann said, smaller farmers like himself have to rely on noticing subtle signs like changing colors of crops.
Along with his summer squash being hurt this year by heat stress, Ahmann said heat stress damaged his tomatoes so bad that only three or four out of 100 of his tomatoes survived.
“Welcome to Arizona in the summer,” Ahmann said.
But the damage of heat stress on his crops isn’t discouraging him.
“I want it to look like the hanging gardens of Clifton,” Ahmann said, “I’m going to keep working on it as long as the Lord lets me.”