Increasing temperatures decrease corn yields
Friday, August 9, 2019
For residents of the Southeastern U.S., hot summers are par for the course. We know our air conditioners will run steadily, especially in July and August, and our back porch ceiling fans will work overtime to keep us cool while we grill out on hot summer nights. Though what we may not have expected — even me, as a researcher in the crop sciences field for the last 25 years — is that the heat would begin to impact our agricultural industry, particularly corn.
Here in the Southeast we would expect crops of all kinds to have a certain amount of tolerance for heat, given that our temperatures and humidity are historically substantially higher than in other areas of the country. But over the last 4 to 5 years, we’ve experienced an increasing number of summer days when the temperature is over 90 degrees. NOAA released data just last week showing that June 2019 was the hottest on-record in the 140 years they’ve been tracking temperatures. The state’s corn crop is, literally, feeling the heat.
When temperatures are consistently in the 90s and 100s, the corn is subject to severe growth issues. The fields don’t properly pollinate, which can cause a loss of the corn kernels, resulting in lower crop yields. In fact, North Carolina’s corn yield has seen a steady decline since 2014, while other areas of the country have experienced year-over-year growth. In 2014, North Carolina’s corn growers yielded an average of 144 bushels to the acre. Last year, that average dropped to 124 bushels, a substantive decrease.
It’s not that there’s not a sufficient market for corn. It’s in high demand. North Carolina is part of what we call a corn deficit area. We eat a lot of corn, and we feed a lot of livestock with corn. We have an ideal platform for sales, but our production quantities haven’t been able to keep up the last few years.
It’s an issue that crop scientists like me are trying to address, and we’re having to make adjustments to the growing process we simply didn’t anticipate. I’m working with farmers on strategies to try to help overcome this climate-induced challenge so that we can restore our state’s corn yields in the future. Climate change is driving these increasing temperature trends. Its impacts are changing the face of an industry as old as the state, impacting farmers’ ability to generate income and maintain fields that have often times been passed down through generation after generation of farming families.
The income issue is real. Margins are always tight for farmers, and they’re working just as hard, perhaps harder, and spending just as much money — if not more — to plant and grow their corn in these increasingly difficult conditions. Much of that additional work and investment has resulted in lower corn yields, not higher ones. The same equipment and manpower is required to harvest both normally- and poorly-pollinated corn, and on top of that, farmers are investing time and resources into developing new strategies to accommodate the issues our changing climate has imposed.
Crop scientists like me will continue to work with our state’s farmers to tackle this challenge. I’ve been working on new farming methods and tactics for our corn growers to test in their fields. We eventually will come up with a strategy that works, at least in the short term, but climate change is catching up to North Carolina’s agricultural industry in tangible ways. We cannot afford to ignore the reality of our changing climate. We have to plan for its impacts the same way we would plan for any other business disruptor and work together on how to mitigate its increasing effects on our lives.
Dr. Ronnie W. Heiniger received a P.h.D., in Crop Ecology and Simulation Modeling from Kansas State University in 1994. He has received the Gerald O. Mott Meritorious Research Award from the Crop Science Society of America for modeling grain fill in sorghum. Heiniger’s applied research programs in the areas of precision agriculture and remote sensing at North Carolina State University have received national recognition. In addition to his research work, Heiniger is the Cropping Science Specialist for North Carolina.