At an experimental farm in Fruita, researchers are fighting drought with pistachio shells
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FRUITA, Colo. — The Colorado State University research center in Fruita looks similar to other farm operations in the valley, except these workers have another full time job on top of planting, growing, and harvesting crops.
Researchers gather data on water usage, nutrient quality of the crops they grow and even the temperature of the soil two feet underground. All this information is vital for CSU projects that look to make agriculture more efficient in a semi-arid environment.
“[There’s] processing and sampling those crops and then sending them off for analysis.
It's really like working on your own farm, but add in the data part of it,” said Michael Lobato, a CSU researcher.
He drives around in a golf cart, irrigating his hay field, and recording exactly how much water is applied to the two halves of the experiment. One half is regular farm ground, the other half has a supplement added into the soil. That’s the side Lobato hopes will be just as healthy, but with less water.
“I record the start and end irrigation data and then the flow rates,” Lobato said. “So I have the data for all season.” That growing season is usually from spring to fall, depending on the crop.
He stops at a big garage, the shop for tractors at the research station, and talks with colleagues about a new harvester they recently got at the experimental farm. The Western Colorado Research Center, as it’s called on the big green sign on L Road, just north of Fruita, has been in operation since 1949.
There are often a dozen different projects underway, and about that many researchers, staff and students at the two white buildings with green metal roofs surrounded by fields and tractors.
Lobato’s experiment is in a two acre hay field on the eastern edge of the CSU property. It’s not visible from the road that goes past the station, or the one that goes between the fields, because the experiment is happening in two feet of soil just below the surface.
The project uses a soil supplement to increase the water holding capacity of the field. That supplement is called biochar, an extremely porous organic material — in this case made from pistachio shells — that absorbs and retains water. Basically, it takes longer for the ground to dry out after it’s been watered, meaning the field needs less irrigation overall.
Reducing water and fertilizer use increases profit margins for agricultural producers. Using less water leaves more in the Colorado River during a period of historic drought and aridification in the western United States. Some rules on how the river is used expire next year. Negotiators for states and tribes that rely on the Colorado have found no easy answers for future water management.
“Increasing water holding capacity in soil is not entirely new,” said Lobato. Soil supplements are often tilled into farm ground, so the benefit may be lost when the field is replanted.
“What's new is the way we put it in the soil is far [more] optimal than tilling it in, and it works differently,” he said.
Lobato used a turf injection machine that aerates and adds sand to golf course greens, and retrofitted it to shoot the biochar into the ground with high pressure water. The vertical injection method means biochar could be added to an established field where tilling the material isn’t an option.
“In doing that, we use a lot less material which is cheaper, just in the sheer cost of the material,” he said.
The turf machine wasn’t made to be used in the middle of a farm; maintaining enough water pressure and volume was a challenge. This practice is still in the experimental and research stage, and is not ready for common use in production agriculture.
“They're used to doing this work on golf courses that have pressurized systems. So now we had to rent a large water pump to do this,” he said.
That was in May of 2023. Since then, Lobato and colleagues on the project, Jerry Nelson and Holly Stanley, have gathered a lot of data.
“Now that we have a year and a half on this project, there's really no question that it improves the water holding capacity,” Lobato said. “We're also seeing more of the soil health benefit side of it.”
Sensors spread out across the test field measure the water content and other variables from zero to 24 inches down. Half the field is a control, without the biochar added, and the other half has the black, grainy flakes embedded throughout.
The biochar section receives half the amount of water the control gets.
“The biochar strips, at any given time, they'll have 23% more moisture in them even after a month, even through the winter with no irrigation.”
Turning the research into a viable, real world practice would take a specialized machine to do the application, instead of the customized turf machine. In the trial, the cost per-acre was around $7,000, for material and equipment.
“If a proper machine was developed and built, you could probably get that down to maybe $1,000 an acre, maybe $700 an acre, and then every year after that, in theory, you could cut your water consumption by a quarter to a half.”
Developing and building new farm implements is beyond the scope of this soil health research.
Biochar itself is expensive, making this use difficult to scale, even if the cost to apply it decreased with a specialized machine.
This and other projects, like one in the Roaring Fork Valley that also uses biochar and aeration, receive funding from the Colorado Water Conservation Board, because of their focus on finding ways to make agriculture more drought resilient. The state is also funding research into using biochar to mitigate pollution from orphaned oil and gas wells.
Lobato says biochar injection would be ideal for high value crops in perennial, undisturbed systems like orchards, vineyards or nut farms.
“If people are looking at ways to cut their water use and cut their inputs of fertilizers that are shipped from around the world and they go up and up every year, and are affected by geopolitics and wars, if you can take that out or reduce that, then that's a great thing,” he said.
