UI Extension researcher sees promise in sainfoin

MOSCOW, Idaho — A University of Idaho Extension researcher is encouraged by preliminary trial results suggesting he may have identified an ideal forage crop for farmers facing drought conditions or reductions in irrigation water.

Sainfoin is a perennial forage legume native to southern Europe and Asia. It is valued for its nutritional quality, drought tolerance and ability to reduce bloating in grazing animals. The crop also grows well in sandy, rocky and alkaline soils and may be more resilient than alfalfa to lime-rich soils.

In a recent trial at U of I’s Kimberly Research and Extension Center, Extension forage agronomist Pramod Acharya found that sainfoin outyielded four alfalfa varieties raised under the same conditions — including one alfalfa variety that’s popular in southern Idaho and is bred to resist applications of glyphosate herbicide. The sainfoin Acharya raised had significantly less protein than alfalfa. However, the crops had comparable relative forage quality (RFQ), which also incorporates digestible fiber and other nutrients that contribute to animal performance.

“Sainfoin yield is as good or better than some of the varieties of alfalfa. Quality wise if we look at the crude protein level it’s way less than alfalfa, but if we look at all of the nutrient levels, it is more or less similar to alfalfa,” Acharya said. “If yield is good and quality is relatively similar, it would be one of the alternatives in this region.”

Farmers with junior water rights throughout the Snake River Plain have had irrigation supplies reduced amid an ongoing drought, and they’re looking for crops they can grow with less water.

In the trial, Acharya planted replications of four alfalfa varieties and two varieties each of sainfoin, cicer milkvetch and birdsfoot trefoil in 20-by-40-foot plots within a 2.2-acre field. Sainfoin, cicer milkvetch and birdsfoot trefoil are all perennial forage legumes that don’t cause bloat in grazing livestock.

Acharya planted the crops in the spring of 2025 and took cuttings during the 2026 growing season on May 21, July 10 and Sept. 15. A cicer milkvetch variety produced the highest yielding second cutting and protein levels in birdsfoot trefoil, which is also considered drought-tolerant, compared favorably with alfalfa.

Acharya, however, was most encouraged by the sainfoin results. His top sainfoin variety averaged 2.6 tons per acre of dry matter across the three cuttings. By comparison, the top-yielding alfalfa variety, which was bred for winter hardiness, averaged 2.5 tons per acre. A popular glyphosate-resistant alfalfa variety yielded 2.4 tons per acre, and a low-water alfalfa variety developed for planting on dryland fields yielded 2.2 tons per acre.

In mid-October, Acharya applied various herbicides to trial plots and plans to use the results to guide recommendations on how to best terminate sainfoin stands. Looking ahead, he hopes to conduct research comparing water usage of alfalfa and sainfoin varieties, as well as nitrogen fixation benefits of the two crops.

Acharya is eager to see if the initial strong sainfoin yields hold up in subsequent years of his trial. His work benefited from a $4,285 UI Extension innovative projects grant. He’s been in close contact with forage researchers in Wyoming and Missouri who are running similar sainfoin trials.

“This was my first time working with sainfoin, but I’m really excited with this particular crop,” Acharya said. “Sainfoin is not grown very much in the U.S., but it has huge potential.”

Media contact

Pramod Acharya
Assistant professor and Extension specialist in forage agronomy
208-423-6652
pacharya@uidaho.edu