Corn Water Truths

In Environmental, Video by Chuck

At the National Association of Farm Broadcasting convention NCGA’s Rick Tolman took time to dispell some myths about the use of water by the corn industry. He’s got some great facts and figures to explain why the numbers being bantered about as doomsday speak are really meaningless when put in perspective with the information those same people don’t say or want you to know.

Here’s an example of some facts you should know from Rick’s latest column:

* More than 85% of all corn produced in the United States is non-irrigated. So, that 4,000 gallons per bushel is mostly rainfall. That rain is going to fall on the land whether it has corn on it or asphalt or marijuana. According to the USGS (U.S. National Geological Survey), if that same land was instead in wheat, it would take 11,000 gallons per bushel. If it were in alfalfa, it would take 15,000 gallons for a similar amount. If it is a paved parking lot, the same amount of rain still falls. So, one perhaps important point left out by the good bug doctor and the headline writers is that most of the water corn needs is not being sucked from the ground or from rivers, but it actually falls from the sky.

* And, looking even deeper, according to the same USGS, an acre of corn actually gives off 4,000 gallons a day in “evapotranspiration,” the combined result of transpiration and evaporation. Over the course of a growing season that would equate to turning that acre of corn into a lake approximately 11 inches deep. Corn is a very remarkable plant. It gives back much of that water it takes up. That water goes up into atmosphere to start the precipitation cycle all over again. In aggregate, the corn crop actually returns more water to the atmosphere than is withdrawn from ground or surface for irrigation.

* Some other USGS statistics that might be of interest and add perspective:

  • It takes 1,500 gallons of water to produce a barrel of beer
  • It takes 1,851 gallons of water to refine a barrel of crude oil
  • It takes 62,600 gallons of water to process a ton of cane sugar to make processed sugar
  • It takes 62,600 gallons to make a ton of steel
  • It takes 2,075 gallons of water to make four tires

(To see more water trivia and facts, follow this link: