Adding clover to grass pastures is one of those rare opportunities stocker operators have to slug two birds with the single proverbial stone.
“Legumes offer benefits in both fescue and bermudagrass pastures. In bermudagrass, legumes extend the grazing season by providing forage in spring before bermudagrass breaks dormancy and the nitrogen that is recycled through grazing and decaying plant material gives a yield boost for the bermuda,” explains John Jennings, a forage specialist at the University of Arkansas (UA). “In fescue, legumes reduce fescue toxicity as well as providing nitrogen.”
For perspective, UA researchers drilled toxic and non-toxic tall fescue pastures with a blend of annual and perennial legumes including hairy vetch (10 lbs./acre), Dixie Crimson clover (10 lbs./acre), and Regal Graze White clover (2 lbs./acre). Seed cost was $47.70 per acre, not including equipment costs or fuel.
According to UA researchers Shane Gadberry and Paul Beck, “During the initial fall, calves grazing toxic or non-toxic tall fescue interseeded with clovers and vetch gained only about 0.1 lbs. more per day than calves grazing fertilized pastures, but at this time, there was very little clover or vetch to be found in the pastures. During the spring, the percentage of clover and vetch improved to around 25% in both toxic and non-toxic pastures.”
Calves grazing toxic endophyte tall fescue gained only 1.0-1.1 lbs./day in the spring, compared with 2.2 lbs. for fertilized non-toxic tall fescue and 2.5 lbs. for non-toxic tall fescue pastures including clover and vetch, the researchers say. “It is recommended that clover stands in excess of 30% be maintained for improvement of gain in toxic endophyte tall fescue pastures.”
Obtaining the benefits comes with challenges, though. According to Gadberry and Beck, “Soil fertility is much more critical for raising clovers than for grasses. Acidic soil pH and low soil potassium or phosphorus can severely limit clover growth or prove lethal to clover plants in areas where grasses alone will thrive. Weed control can be a great deal harder in pastures containing clovers; most herbicides that kill broadleaf weeds present in our pastures also kill clovers.”
Jennings explains adding legumes to pastures is not complicated, but following these steps increases success:
- Most legumes have a higher soil fertility requirement than grasses, so a soil test is the first step. Soil pH should be above 6.0, and phosphorus and potassium levels should be near optimum for best results. Soil tests from several fields can help identify where legumes have the best chance of growing and where major fertility changes are needed before attempting planting.
- Select a legume species and find a seed source well in advance of planting. Your local dealer may not have the desired seed on hand the day before you want to plant. Annual legumes include crimson and arrowleaf clover or hairy vetch. Other annual clovers include subterranean, rose, ball or berseem. Perennial legumes include white and red clover or alfalfa. Each has different characteristics and growth patterns.
- Make sure the seed is pre-inoculated or be sure to purchase the correct rhizobia bacterial inoculant for the legume species you selected. Check the label on the inoculant package to match it with the correct legume. Red clover inoculant does not work for crimson clover or arrowleaf clover.
- Schedule a week window for planting. For fall planting, late September to mid-October works well most years. Legumes can be planted in dry soil and will come up after fall rains. Delaying planting too late waiting for ideal conditions; legume germination during cold weather can reduce establishment success.
- The grass sod needs to be grazed or clipped short, preferably down to 2 in. or less, before interseeding the legume. Short sod allows the seed to reach the soil easily or allows the no-till drill to place the seed at the right depth.
- Make sure to get good seed/soil contact, but don’t plant the seed too deep. For broadcasting seed, pull a drag or harrow over the field before or simultaneously with planting. This opens the grass residue so the small legume seed can reach the soil surface.
- For planting with a no-till drill, set the drill so the disk openers barely cut the sod or even so they don’t cut the sod. Use more down pressure on the press wheels to push the seed into the soil surface rather than depend on the disk openers. Setting the disk openers to cut too deep is a common mistake. The depth of the cut determines the depth of planting, and the seed should not be planted deeper than 0.25 in.
- Graze across the field to control fescue, ryegrass or weeds that may grow in the fall. This allows more light to reach the legume seedling. Remove cattle when the legume is emerging well.
- In spring, rotationally graze the field to improve legume persistence. If the legume is in a hay field, make sure to fertilize the field according to soil test recommendations for legume/grass. This means: do not apply nitrogen fertilizer. Nitrogen will cause excess competition from the grass, resulting in shading and loss of the legume.