Alfalfa: An underappreciated legume

It happens often in our world; the one who does most of the work behind the scenes gets almost none of the credit and is undervalued for their talents. Alfalfa is often the underestimated plant in the agriculture world, known mainly for the hay it produces, but it offers much more than that.

Bruce Anderson, Extension forage specialist emeritus at the University of Nebraska, spoke at High Plains Journal’s Farmer U & Trade Show about alfalfa’s underrated qualities and how it can be an advantageous addition to many cropping systems.

Most producers pair alfalfa with corn to see yield benefits with the alfalfa rotation. Anderson used an example of a study in which the first year of corn following alfalfa increased yields between 9 to 18% and the following year corn yields continued to see boosts. Aside from the benefits to yield, alfalfa can also be a game changer when it comes to weed populations.

“When alfalfa is mowed, weeds are kept at a minimum and that’s probably one of the reasons why corn sees a boost in production after alfalfa,” Anderson said. “The annual weeds in particular are reduced down from swathing and when corn is planted afterward, there is not near as much weed pressure.”

Anderson said producers have opportunities for significant savings on input costs as a result of having alfalfa in their cropping system.

He referenced studies in which absolutely no fertilizer was applied to corn after alfalfa had been grown and the corn still hit maximum yield.

“In fact, the yield in those situations the maximum fertilizer levels were higher for the corn than what existed when we were growing a continuous corn,” Anderson said. “The alfalfa produces nitrogen, so we get a nitrogen effect, but we also get a rotation effect that somehow changes the soil and the growth situation where fertilizer alone is unable to bring the crop that follows the alfalfa up to its maximum growth potential. This is where we get into the real legume credits that alfalfa can provide.”

By planting alfalfa in a cropping system, producers can reduce their fertilization practices on the crop, still get maximum yields and drastically reduce input costs. Although corn is commonly considered to be a crop that benefits greatly from alfalfa rotation, wheat is also planted after alfalfa as well. In studies, Anderson said in the first year after alfalfa production, the wheat yield increases above a non-alfalfa scenario.

“The wheat crop in our study was able to produce almost 20 bushels more per acre because it followed alfalfa, rather than being in a continuous wheat cycle,” Anderson said. “After four subsequent years of continuous wheat crops following one year of alfalfa, yields continued to be above average due the extra nitrogen and benefits of the rotation effect.”

Anderson used one example of several growers who had analyzed their wheat yields after one year of alfalfa and found they were harvesting 44 more bushels an acre over a five-year time period of continuous wheat and, in that situation, it was basically equal to another whole growing season worth of wheat. Another benefit of the rotation effect of alfalfa is that it can break up disease, insect and weed cycles.

“In some cases, with multiple years of alfalfa, we can really get to a point where maybe we don’t need to use insecticides or purchase a cheaper corn hybrid that doesn’t have all the GMO changes,” he explained.

Alfalfa can also improve overall soil health and condition. Anderson said one reason it benefits the soil is that alfalfa grows much deeper roots than other crops—with roots as deep as 10 to 15 feet. This transports nutrients from untapped parts of the soil and brings them up to the surface. When that alfalfa plant it terminated, those minerals are going to be available for the next crop. Alfalfa also improves water infiltration and the overall structure of the soil and makes it easier for crops to produce healthy and effective root systems.

The next time you see a stand of alfalfa in a field, look beyond the hay that it is producing and consider the multiple benefits it offers below the surface that can mean lower inputs, higher yields and healthier soil.

Lacey Vilhauer can be reached at 620-227-1871 or [email protected].