Kura clover (Trifolium ambiguum Bieb.) is a resilient, low-growing perennial legume with significant potential for various agricultural applications. It is also known by names such as Caucasian, Pellett’s, or honey clover, and originates from the Caucasian region of Europe. This plant is a cool-season species, making it well-suited for mixing with cool-season perennial grasses in temperate climates.
Understanding Kura Clover’s Traits
Kura clover exhibits a distinct growth habit with a deep, branching taproot system and rhizomes, which are underground stems that allow it to spread horizontally. This vigorous spreading capability enables it to form a dense ground cover, filling bare spaces and contributing to its persistence. The plant is highly winter-hardy, capable of surviving extreme cold, ice sheeting, and flooding, making it suitable for USDA plant hardiness zones 3a-8. While its initial seedling vigor is low, taking 2-3 years to establish, its extensive root and rhizome system allows it to persist for many years, with some stands lasting over 15 to 20 years. Its above-ground portions are leafy and provide high feed value, with leaves typically more pointed and larger than other clover varieties.
Why Kura Clover is Valuable
Kura clover offers multiple benefits in agricultural systems. It fixes atmospheric nitrogen, which reduces the need for synthetic nitrogen fertilizers. Established stands can fix approximately 150 pounds of nitrogen per acre annually, contributing substantially to soil fertility. Its extensive root and rhizome system plays a role in erosion control, providing continuous ground cover that helps protect soil from loss, even in no-till systems. This dense root network also improves soil structure and water infiltration.
Kura clover is a high-quality forage for livestock, offering crude protein levels ranging from 22% to 25% and digestibility around 85%. Its leafy nature contributes to its high nutritive value, supporting excellent animal performance in grazing systems. Its dense growth habit also helps suppress annual weeds, as it can reoccupy rows and provide weed control during crop production and through the winter. It demonstrates high resilience to grazing and various environmental stresses, including cold, drought, and low-fertility acid soils, making it a robust choice for pastures. It can tolerate continuous grazing due to its deep-seated crowns, which can be 2 inches (5 cm) below the soil surface, protecting them from defoliation.
Growing and Maintaining Kura Clover
Establishing kura clover requires careful attention due to its slow seedling development. Site preparation should include controlling perennial weeds, potentially a year prior to seeding, and preparing a firm seedbed free of clods. Optimal planting times are typically in the spring, from April to May, or in late summer to fall, ensuring adequate moisture for establishment before freezing.
A specific inoculant containing Rhizobia bacterium is necessary for kura clover seeds before planting to ensure effective nitrogen fixation, as this strain is not commonly found in many soils. Seeding rates typically range from 10 to 12 pounds per acre for pure stands or around 6 pounds per acre when mixed with grasses. Seeds should be sown shallowly, ideally ΒΌ inch deep, to promote successful germination. Cultipacker seeders or drills with press wheels are effective for achieving proper sowing depth and good seed-to-soil contact.
Initial care involves managing competition, as kura clover has poor seedling vigor and can be susceptible to shading from weeds or companion crops. It is generally recommended to sow kura clover without competitive companion crops like small grains during establishment. Long-term management often involves grazing, with rotational grazing being more productive than continuous grazing, although kura clover can tolerate both. Close grazing, maintaining a 2-inch stubble height, can favor the clover’s persistence in mixed stands.