A common question for USDA-Natural Resources Conservation Service (NRCS) employees is, “How do I extend the grazing season on my pastures into the winter for my cows?”
All of the warm season grasses like the heat and the longer days of summer. As the days get shorter, they shut down production – which is not good if you are trying to keep your livestock fed and happy without having to stockpile or purchase hay.
Bruce Healy, NRCS district conservationist in Alice, suggests you consider adding a cool season legume to provide winter and early spring grazing. If you have irrigation access, you can expand your selection to include several of the clovers, but under dryland conditions, one of the best cool season legumes for our area is Burr Clover. Burr clover is in the legume family, thus a relative of alfalfa. For the scientists, is technically in the annual medic (clover-like) family, but the burr clover/medic name has been used interchangeably for years, so most people refer to it as burr clover. It has green, serrated leaves and reddish-purple stems.
A native of the Mediterranean region, burr clover was introduced to North America in the 19th century and it has successfully naturalized in South Texas and on the West Coast. It requires about 10-25 inches of rainfall per year and full sun. It succeeds in practically all soils, but prefers loamy to clay soils with a pH of 7 or greater. It is not well adapted to sandy soils. Burr clover is both self-pollinating and self-regenerating. It can be a prolific seed producer. It often has large amounts of hard seed – which germinates years later.
Burr clover is relished by both deer and livestock – but not horses and mules. It may not be the best choice of feed for wool sheep as the burrs will get stuck in the wool, thus decreasing value.
It is similar to alfalfa hay on nutritional values: crude fiber (15-28%), protein (14-28% - average of about 19%), and ash (6-25%). This level of nutrition can help you reduce your hay purchase costs. With this desirable of nutrition, it can be baled for hay.
A localized ecotype – Armadillo – was released from the Texas A&M Agricultural Experiment Station in Beeville in 1998. It is considered the best winter legume for South Texas.
Generally burr clover will germinate in the fall, grow through the winter, start flowering in late January to February, and then mature and die in April or early May – thus getting out of the way of the our normal summer grasses. This winter and early spring growth is when we can graze it – just remember not to graze it too short and to allow it time to reseed prior to it maturity for it to reseed and be in the pasture for future years.
Seedbed preparation is not difficult (as long as there is adequate soil moisture present): graze the pasture to be seeded short, then once it starts to cool off in the fall (Sept to Dec), do a light disking of the grass (not enough to kill the grass, just open the soil surface to allow the clover seed to get into the ground), drilling or broadcasting the seed, and then a light dragging or rolling to cover the seed. Burr clover seed needs to be inoculated prior to planting, like all legumes. Normal seeding rate is 8-12 pounds of seed/acre – remember that seeding depth is about ¼ inch.
Healy encourages anyone considering planting burr clover to get the soil tested to see if it needs fertilizer for best establishment. Often, some Phosphorus and Potassium fertilizer are needed. Healy cautions to be careful to not over-apply Nitrogen.
If you are thinking about planting a cool season clover/medic, just remember that a broadleaf pasture herbicide that has residual properties may prevent you from achieving a successful stand.
As a legume, once inoculated and established, the burr clover will fix Nitrogen from the air, and make it available in the soil to the summer grasses. One source indicates this Nitrogen is worth $30 to $40 per acre – thus it will pay for itself pretty quickly.
Healy indicated there has been some testing of burr clover as a winter cover crop on cropland. It can help suppress weeds, add Nitrogen, and may produce several tons of vegetation – which can help build your soil organic matter – if the conditions are right. You would need to apply a broadleaf herbicide to get rid of it prior to planting of your next crop.
The small yellow flowers, arranged in a clusters of 5-10, are attractive to butterflies and other pollinating insects, although their use is small. Because of the ease of it reseeding, it is not listed as a major pollinator attractant plant.
Few cases of bloat have been documented with burr clover, however, one should keep the potential in mind.
Will burr clover be right for you? Can it extend your grazing season and reduce your hay purchases? Only you can decide.