I remember the day well. I was on a pasture walk about 25 years ago, and the host farmer led us to a pasture that he had clear-seeded kura clover into. The stand was nothing short of awesome. The ground was totally covered with foot-high kura clover plants possessing leaflets the size of silver dollars. I remember asking myself, “Why don’t we grow more of this stuff?”
In a recent University of Minnesota blog, Craig Sheaffer, Nancy Ehlke, and Jake Jungers summarized the current state of kura clover, outlining both its benefits and challenges. The authors point out that it wasn’t for lack of research or promotion that kura clover didn’t soar in popularity. There was plenty of work done on the species during the 1990s. Likely, it was more due to kura’s seed cost and availability, along with an inability to establish quickly.
To be sure, kura clover is not fast to emerge and develop into a productive plant; however, once it does establish, its ability to persist is nothing short of remarkable. The lifespan of kura clover is often measured in decades.
Figure 1. Stand density (ground cover) of sod-seeded alfalfa, kura clover, and red clover over stand age.
Source: Cuomo et al. Agron J. 95: 1591-1594
The Minnesota forage experts note that kura clover’s propensity to survive almost anything Mother Nature throws at it is attributed to its belowground morphology. The plant is a prolific producer of rhizomes (underground stems) that form new secondary plants.
“We found that combined below ground biomass (root, crown, and rhizome) yields within the top 12 inches of soil to be over 1 ton per acre in the seeding year and almost 3 tons per acre in 8-year-old stands,” the authors report. “In these 8-year-old stands, rhizomes and secondary crowns produced from rhizomes comprised about 45% of the below ground biomass. Because of its spreading growth habit, kura clover provides significant ground cover with the potential to have 100 to 150 plants per square foot.”
Establishment demands patience
Kura clover seed is sometimes difficult to find, and the seed costs more than many other forage species.
Establishing kura clover is one thing. Getting kura clover to establish is another. The species is said to sleep, creep, and leap in years one, two, and three, respectively.
Kura’s initial slow growth is related to small seed size, its slow development of nitrogen fixation, and its allocation of nutrients to roots and rhizomes at the expense of foliage growth, note the authors. The clover doesn’t compete well with existing plant species or companion crops. Often, late-summer seedings are more successful than spring seedings because of reduced weed competition.
A specific strain of Rhizobium seed inoculant (Rhizobium ambiguum) is needed when establishing kura clover. Once established, a pure stand of kura clover is able to fix about 150 pounds of nitrogen per acre.
“Kura clover has been successfully established by drilling or broadcasting into conventionally tilled seedbeds and no-till seeded into suppressed pastures, but establishment is more challenging than for red clover and alfalfa,” the Minnesota specialists explain.
Once established, kura clover provides the best yield potential when rotationally grazed at a 28-day interval, but it will also survive more frequent and continuous grazing. The authors explain that when kura clover is subject to continuous grazing, it demonstrates phenotypic plasticity, varying the amount of photosynthetic energy sent to various plant organs and reducing its leaf size and petiole length. As a result, small leaves develop that hug the soil surface to escape defoliation.
As with many other forage legumes, kura clover can cause frothy bloat if conditions are favorable. For grazing, mixing the legume with a grass is advised. Mixtures also have potential to provide higher yield than kura clover monocultures.
Excellent forage quality
Kura clover has an extremely high leaf percentage. It only flowers in the spring and produces no upright stems later in the season. Wisconsin research with kura clover resulted in steer gains of 2.7 pounds per day and 916 pounds per acre per year for kura-grass mixtures. Forage yield of kura clover is similar to red clover but less than alfalfa.
The final storyline is that kura clover is a persistent, versatile forage legume with many beneficial attributes. Unfortunately, there are years when seed is difficult to find and it fetches a higher price than many other common forage legumes.
