Agriculture and Environment: Corn (Maize)

Environmental Impacts of Production: Water Use

Because corn requires large amounts of water, it poses risks of crop failure for producers.

One way to avoid the risk is to irrigate the crop. It is expensive to set up irrigation systems on the off chance that water will be needed in a bad year, however. Instead, irrigation systems tend to be set up in areas that are not suited to produce corn with the rainfall that is normally available.

Unfortunately, ongoing irrigation is expensive and requires large amounts of water in areas where it draws on scarce water and energy supplies. While most corn grown throughout the world is not irrigated, in the United States corn is the second largest consumer of irrigation water (after alfalfa hay).

Over half of all U.S. corn irrigation takes place in the state of Nebraska, where, in parts of the state, the crop could not be grown profitably without irrigation. Unfortunately, the Ogallala Aquifer that supplies all the water for this irrigation is fossilized water.

This means that the aquifer has a limestone cap, and the water being drawn from it is not being replaced. Eventually the water will run out, but before that the energy costs of bringing it to the surface may become too expensive to produce corn profitably.

Corn production is increasing throughout Asia. In China corn is displacing other crops such as wheat and even rice. Increasingly, corn is also being grown with irrigation.