Low-Input Overseeding: Page 5 of 8

by R.L. Dalrymple

Successful Low-Input Overseeding
There are some things to consider to make low-input overseeding with a common drill successful.

When you use low-input drilling techniques, operate the drill slower than usual (2 to 3 mph rather than 4 to 6 mph). Set the springs on the furrow openers with more tension. Drill when the soil can be penetrated slightly with the row openers, which may be immediately after a rain.

Overseeding small grains by using common drills has been very successful in standing erect bermudagrass residue up to 8 inches tall. A range of 2 to 5 inches is excellent. Annual ryegrass, rescuegrass, and legumes require residue heights of 1 to 3 inches.

Livestock, including those with low nutrient requirements at grazing, can be used to control residue heights and litter accumulation. We have used primarily beef cows or steers as second grazers to facilitate successful low-input overseeding (figure 9). These cattle then are part of the low-input process. After use as second grazers, these livestock (especially steers) can be converted to first grazers for better performance on a higher nutritional plane.

Figure 9. Second grazer cattle, with a lower plane of nutrition, being used to graze 8-inch-tall bermudagrass residue to a 3-inch residue and tread in seed after broadcast planting for low-input overseeding. (click photo to enlarge)

Ground litter (thatch) must be considered separately from standing residue, especially in broadcast plantings. Small grains can establish in ground litter up to 1 inch thick, but 1/2 inch or thinner is better. Ground litter for annual ryegrass and rescuegrass needs to be near 1/2 inch or thinner; that of legumes, near zero. If ground litter is too thick for the crop, then it must be opened with a disk, a low-cost drill, or other tool to expose soil for an immediate planting, especially in bermudagrass stands and absolutely in bahiagrass sods. As many seeds as possible need to be near the soil, touch it, or be placed at the proper depth in the soil. Another method of reducing litter is to graze more intensively to reduce future litter, but this method requires more time and several grazing cycles.

The importance of acceptable standing residue and surface litter must, from the viewpoint of good stand establishment, be considered. The proper residue heights and volumes create a better microclimate for moisture than bare soil or excessively short residue, holding much more moisture for a much longer time after rains. This characteristic affords the seed a better, longer opportunity to germinate and establish a well-rooted seedling.

Kind and variety of forages must be considered. All of the small grains work in this syndrome, but cereal rye establishes the best stands and earliest production by far. Barley establishes well, but may not be as productive or winter hardy in northern areas. Wheat and triticale establish almost as well as barley. Oats establishment is the poorest, but it can be satisfactory. Annual ryegrass and 'Stocker' and 'Matua' bromegrass (rescuegrasses) do well in short residue, as do legumes where well adapted.

Proven varieties planted on clean seedbeds generally work well, but there is a possibility that certain varieties might perform better. The better forage varie-ties for any given area should be used. Successful rye varieties include Maton, Oklan, Bonel, Elbon, and Wrens Abruzzi. A wide range of the wheats is expected to do well, but beardless late-maturing wheats perform well in southern Oklahoma. Choices of oat and barley seeds are limited in our region, and use is relative to seed availability. There are many good annual ryegrass varieties, including Marshall, Jackson, TAM 90, and Ribeye.

Legumes also need to be chosen by their success within a region. In southern Oklahoma, hairy vetch, crimson clover, singleterry pea, Austrian winter peas, and arrowleaf clover have done well in low-input overseedings; red, white, and rose clover have not.

Figure 10. Seed being broadcast in the rain to ensure a higher rate of success. (click photo to enlarge)

Date of planting, with other conditions satisfactory, can be as early as four to eight weeks before average fall frost date and as soon as feasible thereafter or simply when the summer forages cease active fall growth in the far southern and southeastern United States. In general, the earlier the planting within the range, the better the production. Grass plantings can continue up to about four to six weeks before the last spring frost date. Barley, oats, annual ryegrass, and 'Stocker' and 'Matua' bromegrass are some of the choices for late-winter plantings in February to very early March.

Annual ryegrass broadcast planted may succeed better if planted after winter begins. We sometimes plant it separately, after cereal rye planting, in January to very early March. This split planting-date technique seems more necessary in broadcast rather than drilled plantings.

Seeding rates should be at the upper limit for the forage and area of use.

Use rain as a planting tool with broadcasting or low-input drilling with grain drills. If the forecast calls for rain and you are ready, plant, or actually plant during the rain. We have done so and it does improve stands (figure 10) compared with planting in dry weather.

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Lowest Cost, Low Input by Managing for Volunteer & Overseeding in Other Grass Residues >