Reseeding Potential of Annual Clovers
Annual clovers (i.e., arrow leaf, crimson, ball, and berseem) are cool-season legumes widely used and adapted in eastern Oklahoma. They improve forage growth distribution, increase forage yield, and quality while reducing nitrogen fertilizer input. Clovers also aid in extending the growing season, thus reducing the costs of winter supplementation. They are generally very digestible and contain high levels of crude protein which lead to increased animal performance and profitability. Growing clovers with pasture grasses greatly enhances cost effectiveness in forage/livestock production. However, in some instances annual clovers are not considered dependable in their ability to reseed.
Annual clovers complete their life cycle each year. They are usually planted in the fall, and they cease production by late spring. Clovers can be re-established annually by either replanting or allowing plants to propagate depending upon reseeding ability. The dependence on natural reseeding might not be the most practical approach because of the increased risk of establishment failure. To establish adequate stands relying on natural reseeding depends on favorable environmental conditions along with grazing management practices in late spring to enhance clover seed production. Most clovers that have reseeding potential will also produce a large percentage of “hard” seeds. A hard seed is a seed that does not swell or germinate within its established period of viability. A hard seed has a tough impermeable coat that does not allow water or air to reach the embryo, which delays germination for long periods of time. Hard seed may survive passage through the digestive tracts of animals and can remain viable in the soil for more than 15 years.
Delayed germination by hard seed of annual legumes grown in harsh environments helps maintain stands when conditions are not favorable for seed production in a particular year. The quantity of hard seed depends on the conditions that existed during seed formation and maturation. For example, the number of hard seed during drought conditions can increase by 40 to 60%. For natural reseeding to occur, grazing and hay harvest should be managed to allow some of the clover to mature in late spring for seed production. Clover species that produce a high percentage of hard seed provide more dependable volunteer stands than those that produce more soft seed. Table 1 lists some common annual clovers that have the potential to reseed and their characteristics.
Grazing Management for Reseeding
Grazing until early April often results in more seed production compared to not grazing at all. This is due to heavy, dense growth resulting in lodged plants, matted forage, and reduced numbers of blooms. To allow adequate reseeding, remove livestock from the paddocks or reduce stocking rates in late April or early May when the clover starts to flower or bloom. During the 4- to 7-week flowering period, seeds mature in the lower portion of the seed heads first, and some mature seed should be present by early mid- to late May. Keep in mind that when having clover mixtures in the same pasture, flower production might vary due to maturity of the species. It might be necessary to keep the animals off the pasture for a longer period of time. Differences in seed and flower production among species can range from 20 to 40%. Once the seed heads have matured, livestock could be returned to grazing those areas. Some clovers with a decumbent growth habit can tolerate close, continuous grazing and still have optimum seed production, resulting in a greater chance to reseed in pastures than clover species with a more upright growth habit. Successful establishment of annual legumes is achieved only with the use of varieties that have both high persistence and high productivity within the specific environment in which they are introduced. Reseeding annual legumes can play an increasingly important role in winter forage production because the cost of annual planting would be eliminated.
Drop by the Murray County OSU Extension office for a more detailed fact sheet and take advantage of the area Extension Agronomist by contacting us. We’re here to serve you.
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