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New Mexico State University

New Mexico State University

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NMSU Drip Irrigation Study Could Alter Farming Practices in Four Corners Area

FARMINGTON - Drip irrigation research in the sandy loam soils of northwestern New Mexico could help farmers in the semiarid Four Corners make a transition to more efficient irrigation.

By switching from traditional systems to drip, local farmers can reduce water, fertilizer and pesticide use while increasing crop yields and profitability, said Mick O'Neill, superintendent of New Mexico State University's Agricultural Science Center at Farmington.

"Given the semiarid conditions here, we need to find much more efficient methods of irrigation, and this technology can help a lot in that regard," said O'Neill, who is supervising the drip irrigation study. "It has the potential to increase yields with less water while reducing inputs such as fertilizer and herbicides. That gives it tremendous appeal for the big commercial producers as well as the small-scale, resource-poor farmers right here on the Navajo Nation."

Most local farmers use flood irrigation and sprinkler systems. With those techniques, about 30 to 50 percent of water is lost to evaporation, leaching and runoff. Drip irrigation, which supplies water directly to plant roots trough a perforated tape buried permanently under the beds, allows 90 to 95 percent of water to flow directly to plants, O'Neill said.

Instead of alternately drenching and drying plants, drip tape provides a small, constant supply of water that produces healthier plants and higher yields, he said. The need for herbicides and pesticides is reduced because water flows directly to the crops rather than to weeds.

In southern New Mexico, where NMSU researchers have already produced guidelines for local conditions. Chile farmers are gradually adopting drip irrigation. But in the northwest, such guidelines are lacking, something O'Neill hopes to change.

"We need to figure out the wetting characteristics for the particular soils of this area so that we know how much water crops use with drip irrigation and at what depth the tape should be buried," O'Neill said. "If we place it too far down we won't get adequate plant germination, but if we place it too high, field equipment could damage the tape when harvesting."

The experiment will take place on an 8-acre plot at the center, where a drip irrigation system complete with ground tape, water pumps, filter, fertilizer injection tools and computer monitors was installed in May and June.

The drip tape was placed at four different depths: 3, 5, 7 and 9 inches. The field is planted with potatoes and oats to study how those crops perform.

In addition to soil wetting characteristics and overall water use, the study will measure the level of fertilizer that must be pumped for optimum crop productivity. The center will also study weed and pest control by injecting herbicides and pesticides through the system.

An $80,000 Bureau of Indian Affairs grant, channeled through the Navajo Agricultural Products Industry (NAPI) in Farmington, financed the system installation. When the first study results are reported in early 2002, NAPI expects to use center recommendations to convert part of its 65,000 acres of irrigated land to drip irrigation, O'Neill said.

Still, it may take time to convince small- and medium-scale farmers to adopt drip systems since they require careful monitoring to avoid damage when tilling and harvesting fields, and they can cost from $1,200 to $1,500 per acre to install.

"Farmers must recoup investments over 4 or 5 years, but a well-managed system can last up to 20 years, so the farmer will eventually save money," O'Neill said.

For resource-poor farmers, rudimentary drip systems can also be installed for as low as $125 to $150 per half acre, he said.