Efficiency helps farmers cope with shortage

Issue Date: October 7, 2009
Kate Campbell

Soil expert Dave Goorahoo of California State University, Fresno, left, reviews operating programs on a satellite-guided tractor with Chuck Dees, irrigation manager for Stamoules Produce Co. The Mendota-based vegetable farm is a leader in deploying innovative irrigation technology.

Farmers talk about "crop for drop" to gauge the efficiency of food production compared to the amount of water applied. And Chuck Dees, irrigation manager for Stamoules Produce Co. in Mendota, likes to talk about "smart water."

With 14,000 acres of vegetable crops—corn, melons, peppers and broccoli—using water wisely is more than just a good idea. These days, with a three-year drought and delivery restrictions cutting federal water supplies to a mere 10 percent of contract amounts on the San Joaquin Valley's west side, irrigation practices need to be ingenious.

Dees said the company has been researching and investing in emerging irrigation technology for more than a decade and he said, "Every time we get more efficient, it seems to come out at the end. When we make a gain in water conservation, it costs us less money for water. When we use water smarter, we get better yields. When we get better yields, we get a better bottom line."

Reports indicate that in the last six years, farmers in the San Joaquin Valley alone have invested more than $1.5 billion in high-efficiency irrigation systems.

"Strides in irrigation technology are encouraging, but improvements in efficiency are incremental and are a medium-to-long-term strategy," said Chris Scheuring, California Farm Bureau Federation Natural Resources and Environmenal Division managing counsel. "Efficient technology will clearly be one way of addressing water shortages. But farmers certainly aren't able to conserve their way out of the current crisis. And we know California must develop additional water supplies to avoid chronic shortages in years to come."

He added that California farms such as Stamoules Produce continue to support irrigation research and adopt technology, as well as hire highly trained specialists to manage irrigation practices.

Dees said water is a big expense and it's hard to gauge how much water or money farmers should expect for 2010 crops. As a result, it's hard to plan and gain the financing needed to keep farming. Stamoules will be cutting back on planted acreage, Dees said.

"Without water, there is no crop," he said.

The crops grown on the ranch require an investment of about $4,000 an acre to grow and harvest and, Dees said, the farm has made a considerable, ongoing investment in water-efficiency equipment.

For Stamoules Produce, irrigation efficiency includes using buried drip tubing, in some cases drip lines that have been in the ground for a decade or more, set 10 inches deep, just at the root zone for the crops grown on the farm. The drip lines are buried beneath 80-inch-wide beds with two drip lines set 28 inches apart in the center of the bed.

Planting and cultivation on the year-round operation are done with satellite-guided tractors that operate within the furrows and maintain equipment accuracy within a fraction of an inch of the drip lines, but still do not disturb them. Irrigation is triggered by a sophisticated sensor system that takes into account a variety of climatic conditions and crop needs.

Another innovation is the installation of seamless, thin-wall tubing with molded emitters. The seamless design helps prevent rupturing and a 10-mil thickness provides multi-year endurance.

Emitters are molded inside the tubing and Stamoules uses a standard emitter spacing of 18 inches. A large emitter flow path helps prevent plugging and has mini-filters that trap small particles.

"We haven't had a clogging problem," Dees said. "But we still use overhead sprinkling for germination. That's because the precise, computer-controlled system doesn't use enough water to leach salts, which can affect germination."

In the past, the farm used about 3.5 to 4 acre-feet of water per crop. Today the average is closer to 1.5 to 2 acre-feet.

Bell pepper yields, for example, have gotten a particularly big boost using the new technology. Dees said more precise water management meets plant needs at different growth stages and harvest crews can work even while fields are being irrigated.

"Our quality is good right to the end," he said. "Our honeydew melons have yields 25 to 30 percent more using buried drip lines. Sweet corn production increased 15 percent."

Dees said the farm has put 1,500 acres on an air-injection system.

"Not only does it keep the lines and emitters clear, but it also provides additional air to the root zone," he said. "That helps combat compaction."

Soil scientist Dave Goorahoo, who works with the Center for Irrigation Technology at California State University, Fresno, has conducted field trials with Stamoules. Recently he has been working on salinity research and management projects because, as less water is used, salt buildup in the soil is a problem.

"We've been developing a variety of technologies for more efficient water use that take into consideration the variability in fields of soils, crop types, climate and water availability," Goorahoo said. "It's about getting water on the crops in the right amount when it's needed."

With water supply reliability uncertain on farms, he said, "we hope the technology will continue to be a growing part of the solution for agriculture and the state's water supply."

But, he emphasized, automatic systems don't remove the need to check fields in person.

"If you don't understand what's going on with your crops and your land, you can't really manage the technology for its maximum benefit," Goorahoo said.

"Technology is a tool and when used appropriately, such as here at Stamoules Produce, it can not only save water, it also can increase yields and improve profits. But, you've got to be smart about deploying the technology," he said.

More information on emerging irrigation technology is available from the Center for Irrigation Technology at cati.csufresno.edu/cit.

(Kate Campbell is an assistant editor of Ag Alert. She may be contacted at kcampbell@cfbf.com.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.