U.S. Farm Irrigation Practices at a Glance

By David Wallace, Co-Founder and CEO of FarmHQ

As someone who grew up around farm irrigation and now leads an agricultural irrigation technology company, I’m frequently asked, “What percentage of farms in the U.S. use each type of irrigation?”

It’s a big question – and a high-level analysis of the 2018 U.S. Department of Agriculture (USDA) National Agricultural Statistics Service’s  USDA NASS Census and its Irrigation and Water Management Survey of Irrigated Agriculture provides some answers. Every five years, the USDA surveys U.S. farms to understand what, where, how, and how much growers are irrigating. The data offer rich insights about agricultural water use in the U.S..

First, how much water is used on farms in the U.S., and how is that usage spread across the country? Unsurprisingly, California dominates the rest of the country both in terms of irrigated area and total volume of water applied, with close to 25 million acre feet of water applied to 8.4 million acres in 2017. Across the U.S., irrigation is more heavily concentrated in the Southwest, and decreases as one travels northeast toward Maine.

The census provides more detail about what types of irrigation systems are in use throughout the country, grouping irrigation methods into three main categories:

• • Drip Irrigation/Trickle Irrigation: subsurface drip, soaker hose, trickle emitters, etc.. These are generally the most efficient systems from a water use perspective but are expensive to set up and require frequent maintenance and inspection to operate effectively.
  • Sprinkler Irrigation: Center pivot irrigation systems, wheel line irrigation systems, solid set irrigation, irrigation travelers, hose reel irrigation systems or hard hose irrigation reels, big gun irrigation sprinklers, etc.
  • Gravity Irrigation: Flood irrigation, furrow, rill, etc..

While all states have small pockets of each type of irrigation, there are very few states that use all of these methods in equal proportions. If we color the map based on which of the three categories covers the most area in each state, some interesting trends emerge:

• More than half of all states rely on sprinkler irrigation for the majority of their irrigated acreage.
• California is the only state in which both drip and gravity irrigation are used more widely than sprinklers.
• Gravity irrigation remains the dominant method in nine states including, surprisingly, desert states like Arizona and Nevada. 

What I will leave you with is this interesting visualization: if we combine the irrigation method map with the first heatmap showing the distribution of irrigation totals across the country, we get a really neat (albeit simplified) qualitative look at how U.S. growers irrigate their crops. California is in a league of its own, the sprinkler is king throughout most of the country, and gravity is hanging on in a few key strongholds.

Irrigation methods vary widely across the country, but visualizing predominant irrigation method with relative usage shows us the leaders in each of the major methods: California is the undisputed leader in drip irrigation; Nebraska is home to the most irrigated acres of center pivot irrigation of any state; and for flood/gravity irrigation, no state has more than Arkansas.

The next USDA Irrigation and Water Management Survey will be released in November 2024. I’m looking forward to diving into the results when they’re released and understanding how practices have changed over the last five years. Stay tuned!