Located on the outskirts of Yuma, in the Golden Plains region of northeastern Colorado, the Irrigation Research Foundation (IRF) is in a perfect spot to work out new ways to make better use of water.
Water here comes from the Ogallala Aquifer. It produces good crops of corn, wheat, alfalfa, edible beans, sugar beets, grain sorghum and potatoes. But the water level in the aquifer has steadily declined since irrigation became common in the 1960s. In addition, farmers need to conserve water to increase flow in the Republican River to abide by a compact with Nebraska and Kansas (see page 44).
IRF is a private, nonprofit, independent research and demonstration farm. It exists to promote proper water usage and to provide a technology testing ground.
Charles Corey, IRF's farm director, says that the past 15 years of work provide proof that good crops can be produced with less water than the average farmer applies.
"Our total application goal as a farm, after numerous trials, is 15" per acre,” Corey says.
The farm tests products and technology from many companies. These days, Corey is intrigued by a moisture probe developed by AquaSpy, an Australian company. Two inches in diameter, the probe can go 5' deep, reading moisture levels through the soil depth.
"It tells how much is being taken up and how much is lost. The plant may look stressed, but the AquaSpy tells us that it's OK for another four days. It gives us more time to utilize exactly what is in that profile,” Corey says.
"Without a doubt, we have historically overirrigated. Now we're playing catch-up, and it takes a long time to recharge the aquifer. We should have taken these steps 10 years ago. We have years of data saying we can grow crops on 40% less water than average. Maybe you don't get the top yields, but if you can reduce input costs and produce 240 bu. to 260 bu. corn rather than 280 bu., why not do it?” he says.
Tailoring irrigation to field conditions helps save money and water, too.
"Producers know their fields' weak spots. They can see that the corn in one area looks yellow, that they've overwatered it. They should try to hit that middle area and use that knowledge to know the best place to put probes. You don't want to put that probe in the low ground where there's runoff,” Corey says.
Many farmers in this area began strip-tilling corn to conserve water. It's a move Corey endorses, demonstrating with a probe.
"The probe easily goes into strip-tilled soil, and you're keeping residue where it needs to be. Yet when you plant the seed, the roots go straight down and use what would have been runoff. Where it's disked soil, the roots hit a 12" hardpan and go laterally. In strip-till, the hardpan is shattered and that allows the roots to get in deep,” he says.
"That's why we see a big difference in yields. Farming here is totally different than it was 10 years ago. You can't use strip-till without guidance systems. You have to hit that sweet spot. Everything changed because of that,” he says.
IRF continues to look at a range of new systems, from hybrid response to differing amounts of water to plant population studies.
Drought Tolerance and Rotation
If the much-touted drought-tolerant corn hybrids hit the market and perform well, it could mean other crops get some additional water.
"I think with drought-tolerant genes, we're going to see more rotations. If producers can use only 15" of water a year, let's say, and you have a half-circle of wheat with a half-circle of corn, if the corn takes up only 4" of the water, you could put the rest on the wheat,” says Charles Corey, Irrigation Research Foundation farm director. "That crop rotation will help take care of insects and other things and will be worth its weight in gold. You can put in a corn crop that takes less water and, on the other half of the circle, put in something else and still keep water use at a low level.”
You can e-mail Charles Johnson at firstname.lastname@example.org
- March 2010