What is the difference between dryland and irrigated farming? Follow along as Chad dives in!
by Chad Steiner
About 70% of the Earths fresh water is used for agriculture. There are mentions of some parts of the World running out of fresh water in the next decade. Whether its agricultural use for food or clean fresh water sources being polluted, fresh water is a precious resource. Understanding where our fresh water is used is vital to how we manage and protect it. Let’s put this in perspective. In 2012 the USDA stated the U.S. land area at 2.3 billion acres. 1.3 billion acres were in agricultural use (Source USDA) – crops (392 million acres), range and pasture, grazed forest land, etc.. Of the 392 million acres of cropland, about 58 million (15%) were or are irrigated (let’s assume these numbers are close to todays split). I’d like to emphasize this – that means 58 million were “irrigated” using fresh water sources and 334 million acres of cropland were or are farmed “dryland”. The State of Washington is about 46 million acres total. So an area over 20% larger than the State of Washington – 58 million acres is the cropland that gets irrigated in the United States. But wait, you might be asking, what is the difference between irrigated farming and dryland farming?

Dryland farming is where crops are grown and dependent ENTIRELY on natural rainfall in the location they’re grown. NO supplemental irrigation is used. I’ve been asked, “couldn’t you just drill a well?”. The answer is not cut and dry, but on a basic level, most wells don’t produce enough water supply to grow water intense crops on large acreage. Significant number of acre crops grown as “dryland” crops in the United States are corn, wheat, soybeans and cotton. And for example – wheat needs 12-15” of rainfall to produce a crop. In areas that receive more rainfall yields may be higher. The caveat with dryland farming is the reliance 100% on what Mother Nature delivers. Each year crop yields can be different and in some years, farmers might experience crop failure if there’s no rain at the right time. This is also where soil health plays an important role. Regenerative soils have the ability to absorb and maintain moisture vs. conventional or heavily tilled soils. The beauty of dryland farming is synchronizing with nature and working with it to produce food for us all to eat. This is a good spot to emphasize the large – maybe we call them “staple” – crops like corn, wheat, soybeans and cotton are mostly grown “dryland” with no supplemental irrigation. The beauty of irrigated farming is the broad diversity of crop choices and being in control of how much and when water gets applied.
Going by the numbers, irrigated farming is a very small part of crop production in the United States and globally. It is however a large consumer of fresh water. There have been massive improvements in water use efficiency and application efficiency in the last 30-50 years. In other words, we’re way smarter with how water is used for crops equating to massive reductions in waste. Plus there are tools to help measure and guide “when” to apply water – like Wilbur-Ellis’s Probe Schedule we use on our farm. But before I go to much deeper, I think it’s important to understand where irrigation water comes from. I like to think of irrigation as either coming from “surface” water sources or “ground” water sources. Examples of surface water are lakes or rivers. And most likely these “surface” waters are diverted or directed into a water system. These water systems are often times Federal, State or Local Municipality projects. One large example is the Columbia Basin Irrigation Project. The Columbia Basin Project originates with large pipes pumping uphill from behind the Grand Coulee Dam into the 28 mile long Banks Lake where it then flows into canal’s and is carried to over 700,000 acres of farmland from Ephrata to Tri-Cities and East of Moses Lake. This project pulls less than 5% of the flow from the Columbia River. The farmers using the water would have ditches, pumps and/or pipes to deliver water to their crops. In many cases all that is needed is gravity. Pause for a moment to imagine the diversity of crop options irrigation water opens up – sweet corn, beans, apples, cherries, potatoes and more! In an area like California add almonds, tomatoes, lettuce and strawberries.
Let’s circle back to “ground water”. The other major way I think of irrigation water is ground water. Think wells: drilling wells and drilling deep wells in some cases. Then pumps. And, pumps require electricity of some kind – either from say a diesel generator or from electricity. The cost is definitely something to consider with either of these options – as in, the cost of diesel fuel and the cost of electricity (especially in California). A nuance with ground water use I’d like to highlight is – how does the ground water get replenished? I can think of 3 areas in the country I had first-hand experience where growers recognized the need to diversify water sources because the aquifer or ground water they were utilizing was disappearing from irrigation use faster than it was filling back up. The three were the Odessa aquifer East of Moses Lake, The Ogallala aquifer stretching from North Texas to South Dakota and ground water in the San Joaquin Valley of California. These areas have made incredible efforts to become organized and seek out ways to sustain their water sources. In fact, the Columbia Basin Irrigation Project has continued expanding – freeing up demand on the Odessa aquifer. Ground water is interesting and complex. All our fresh water sources must be monitored. And I’m happy to say that in my personal experience, growers and those in the industry have been on the leading edge as stewards of their water resources.
I’m going to conclude with some fun numbers.
- 3.5 acre feet of water is 1,140,480 gallons of water. That’s what our farm is eligible to receive from the Lake Chelan Reclamation District annually per acre.
- A green pepper plant needs about 4.5 acre feet of water to produce.
- An apple tree needs about 4.5 acre feet of water.
- Wheat (as shared before) only needs about 1.5 acre feet.
- Wine grapes need 2 – 2.5 acre feet of water.
I hope this has been insightful and helpful as we strive to share pieces of the puzzle on farming with you. Have a great weekend everyone.

