NMSU Horticulturist Wants to Make Most of Water
Date: April 16, 1997
Editor: D'Lyn Ford (505) 646-6528, dlford@nmsu.edu
LAS CRUCES -- George Dickerson, horticulture specialist with New Mexico State University, knows that when farmers give their tomatoes, cucumbers and chiles a drink, they want it to last.
That's why this season, he's studying whether using compost and a water-absorbing gel can help the state's small-scale, high-value crop growers make the most of the state's limited water supply.
"New Mexico, along with the rest of the southwestern United States, has been in an extended drought for four to five years, resulting in reduced yields of both agronomic and horticultural crops," Dickerson said. "Also, limited snowpack in watershed areas has reduced the water available for irrigation. Fields treated with compost could retain more of what limited moisture occurs naturally and moisture applied artificially."
The Cooperative Extension Service project includes research plots in nine counties throughout New Mexico. "We have a good representation of growers and locations," he said.
The growers each decided what crops they wanted to try in the 30-by-50-foot plots. "I'll be looking at the effects of four combinations of compost and a water-absorbing gel on plant growth and yield of several horticultural crops, including cantaloupe, chile, cucumbers and tomatoes," Dickerson said.
Composts have long been known to increase the water-holding ability of soils, he said. For the study, Dickerson will test green waste compost that Albuquerque's state-of-the-art compost facility began making in 1996. Green compost contains only vegetative, yard waste, no animal or human waste that can make the compost too high in salt.
The non-toxic, synthetic gel is similar to the moisture-absorbing material found in many brands of diapers today. When mixed in with the soil and then watered, the small granules swell to the size of marbles.
The research plots also will be covered with a special, woven, plastic mulch that allows moisture through, keeps the soil warm and reduces the need for weeding.
Plants will be started in special transplant tubes in the greenhouse. "After transplanting, we'll give the plants a good drink -- load up the soil with water," Dickerson said.
From then on, the plants will get only natural rainfall or limited water from a portable drip irrigation system, depending on the weather conditions. At the end of the season, yields from crops grown in the research plots will be compared to what growers achieved under full irrigation.
One of the cooperating farmers, Harold Hobson, of Hobson Farms Inc. located 6.5 miles south of Roswell in Chaves County, said he is interested in finding out how well all four factors being tested in the trials will work. "The gel, the compost, the plastic and the transplants all have potential," he said.
About 25 percent of Hobson Farms' 1,200 acres is devoted to growing produce, especially chile.
"We grow a lot of vegetables, and we're interested in any method that uses less water," Hobson said. "We're also very interested in conserving natural resources to benefit the people that follow us."
Hobson said he will be eager to find out if the techniques tested will be cost-effective for large vegetable plots or just for smaller ones.
As part of the study, Dickerson will compare the cost of the extra materials with the cost savings of water and the price received for the crops at farmers' markets or roadside stands.
The initial costs for the gel and plastic may seem high, he said. But the gel can last in the soil for several years, and the plastic mulch is treated to withstand the sun's damaging rays and can be used for as many as 10 years.
"Even if the costs do turn out to be too high for growers, these treatments may work well for home gardeners," Dickerson said.
If the technique using compost does work, he said it would be a win-win situation for New Mexicans by recycling yard waste into water savings.