August 1, 2006

 

US researchers to look for alternatives to alfalfa in dry states

 

 

Researchers at New Mexico State University's Agricultural Science Centre at Tucumcari are examining alternative crops that could produce dairy-quality feed with less water.

 

Although alfalfa is one of the most water-use efficient forage crops, it still requires a lot of water to maximise production, said forage agronomist Leonard Lauriault of the Tucumcari centre.

 

As water become scarcer, producers need alternatives to alfalfa that can still produce sufficient forage to meet the demands of New Mexico's growing dairy industry, Lauriault said.

 

Annual crops are valuable in semiarid regions, such as New Mexico, because they can be planted to take advantage of seasons of high precipitation, Lauriault said.

 

In New Mexico, both small grains such as wheat and triticale, which are winter annual grasses, and sorghum forages, which are summer annual grasses are used.

 

Although both are lower in quality than alfalfa in regard to protein levels and digestibility. Thus, planting an annual legume with the annual grass can be used to increase the protein content.

 

Hairy vetch and Austrian winter pea, both winter annual legumes, are widely adapted to environmental conditions in New Mexico and the Texas Panhandle, where the dairy industry is booming.

 

The yield and quality of each species, whether grass or legume, is determined by maturity. So researchers needed to plant different combinations of grasses and legumes to find the best match, Lauriault said. Researchers also needed to make sure any possible yield decrease of the mix due to competition by the legume was not significant to reduce the overall value of the increase in forage quality.

 

The researchers experimented with different grasses and legumes and found that yield of wheat or triticale mixed with Austrian winter pea was greater than the other small grains species, whether grown as monocultures or in mixtures.

 

However, Alfalfa is still the dairy forage of choice and it has versatility beyond that industry, Lauriault cautioned.

In the meantime, when water is limited, producers can increase quality of wheat, triticale and oat forage by planting it with Austrian winter pea, he said.

 

Researchers are seeking a warm-season legume to plant with the sorghum forages to improve quality of that forage.