Nebraska’s Irrigation – Why and How

By: Dawn Kucera

Driving across the state, you will see long spans of metal over field after field. That is called center pivot irrigation. Let’s talk about it.

Nebraska is the most irrigated state in the US. We have 9.1 million acres of irrigated cropland. It is a vital part of Nebraska, providing corn and soybeans for livestock feed and fuel.

Irrigation in Nebraska can be dated back to the late 1800s. Canals and ditches were used to move water from rivers to fields by farmers and irrigation companies. After World War II, pumping ability gave access to the Ogallala Aquifer and farmers were able to expand production of crops that needed more water than rainfall provided. Center pivot irrigation has taken the place of most other methods of irrigation because its design is the most efficient use of water. Some surface water is still used; however, 89 percent of irrigation comes from groundwater sources.

Nebraska is very diverse in average rainfall, ranging from 33 inches in the southeast to 13 inches in the Panhandle. In addition, every year varies when that moisture comes. We know that it takes 20-22 inches of water in growing season to produce corn and 19-21 inches to produce soybeans. This is just a generalization as soil type, soil fertility, seed genetics, and crop protection methods all play a part in the equation.

Irrigation allows farmers to supplement when rainfall is not adequate for the growing crop. It is important to note too that the crop’s stage of growth plays a part in when irrigation may be needed. For example, at corn’s peak water usage, it is needing up to .5” per day. Farmers monitor their crops constantly to gauge how much they need to mature efficiently.

Irrigation has evolved since its beginning. Nebraska has increased the amount of corn produced per gallon of water by 70% between 1990 and 2014. Soybean production has increased by 80% in that same time frame. We have learned that over-watering is detrimental to the crop’s yield, wastes water and energy (electricity or diesel fuel) and is not healthy for the soil.

Farmers are required to work with their local Natural Resource Districts (NRDs) on placing irrigation in fields. Local NRDs monitor water usage on irrigation wells with flow meters, and many have set yearly usage limitations. This can vary between NRDs. In addition, farmers can be limited on when they can irrigate during peak usage hours of electricity in extremely hot weather. Electric pivots will not be able to run until power is restored to the unit, usually in the evening hours.

So, how does irrigation affect you? The protein on your plate most likely ate corn or soybeans grown using irrigation. Farmers work hard to steward the water we need to provide the feed for the food you eat and fuel you use in your cars.