By Blake Jackson
When hot and humid weather strikes, some people blame lush green cornfields for making the air feel even stickier. However, unless you're actually inside those fields, corn isn't the cause of your discomfort.
While corn does release water through a process called transpiration, its contribution to overall humidity is minimal. On average, a cornfield transpires between 4,000 and 8,000 gallons of water per acre each day.
Still, this amount pales in comparison to the approximately 160,000 gallons of water already present in the atmosphere above one acre on a hot, humid day.
Corn plants, like all vegetation, use transpiration to regulate temperature and support physiological functions. Once the leaves have fully covered the field and sunlight is mostly intercepted, transpiration becomes the primary source of moisture loss.
Factors influencing transpiration include soil moisture, plant water content, air temperature, humidity, sunlight, and wind speed.
When relative humidity (RH) is high, plants lose less water. In Nebraska, peak cornfield water loss is around 0.33 inches per acre per day equal to about 8,960 gallons.
In regions east of the Missouri River, daily transpiration estimates average closer to 4,000 to 5,000 gallons per acre, particularly when RH is around 50%.
Even though this seems like a lot, it's minor compared to the moisture already suspended in the atmosphere. For example, at 86°F and 50% RH in Kentucky's Bluegrass Region, the air above one acre holds about 160,000 gallons of water.
For context, one inch of rainfall equals roughly 27,184 gallons per acre. July rainfall recorded by the Kentucky Mesonet at Spindletop Farm measured 3.1 inches, which equals 84,270 gallons per acre.
Moreover, an acre of corn can absorb up to 35,000 pounds of CO₂ and release about 25,000 pounds of oxygen throughout the season.
While it may feel more humid inside a cornfield due to blocked airflow and localized transpiration, outside of those rows, corn has little impact on regional humidity levels.
Photo Credit: gettyimages-awakr10
Categories: Kentucky, Crops, Corn