The following management practices will promote vigorous, healthy plant growth and also extend the pasture's productive life.
Grazing Management
Divide the total acreage into paddocks so that it will be possible to rotate among them. The amount of time necessary to permit forage regrowth and increase plant vigor varies with stocking rate, time of year, rainfall, and the forage species present. In most cases, a rotational grazing program is based on 2- to 4-week rest periods.
Horses should be removed from a pasture when tall fescue and orchardgrass are 4 inches in height and Kentucky bluegrass and bermudagrass are 2 inches in height. Legumes are less sensitive to grazing height than grasses but will be weakened by close, continuous grazing.
Pregnant mares should be removed from endophyte-infected tall fescue pastures 2 to 3 months prior to foaling.
Close grazing favors bluegrass and bermudagrass over tall fescue and orchardgrass. There is more leaf area close to the ground (and below the grazing height) with bluegrass and bermudagrass, which provides energy for pasture regrowth. Try to avoid continuous, close grazing of any one area because this quickly reduces the amount of legume in the stand and increases the presence of weeds. On the other hand, lax grazing pressure allows the forages to mature and become less palatable and nutritious. If the grass is beginning to head, consider making hay or clipping that acreage.
Horses may selectively graze one forage species in preference to another and may avoid eating forage soiled with manure. One solution to such uneven grazing would be to follow the horses with other species of livestock (if you have them) because they will often graze what horses ignore.
Avoid grazing newly seeded areas when the soil is wet and muddy, as the horses' hooves can cause damage to the small forage seedlings. A holding area or dry lot is recommended for such situations.
Clipping Pastures
After grazing, pastures may be mowed to promote uniform leafy regrowth and a more pleasing appearance. Clipping is also beneficial since pasture regrowth is more palatable and nutritious than mature plants. Clipping also helps reduce weed pressure and the risk of eye irritation caused by mature seed heads.
Annual Fertilization
Nitrogen fertilizer will be needed each year in any predominantly grass pasture. The amount of N applied will depend on the yield goal for each field. Nitrogen will cause cool-season grasses to thicken up, especially if applied in late fall. To revitalize a stand of grass, make sure the grass is short in August-September. Exposing the bases of cool-season grasses to sunlight in the early fall stimulates the formation of new shoots. Apply 50 to 60 lb N/A in November or December. Nitrogen fertilization encourages the growth of these new tillers. Ammonium or nitrate forms of nitrogen are preferred over urea for fall fertilization because some urea is lost to volatilization. If urea must be used, increase the rate by 15 percent to account for the loss.
Prior to winter, graze or clip the fall growth to a height of 6 inches or less for tall fescue or orchardgrass and 4 inches for bluegrass. Excessive top growth of cool-season grasses going into the winter will lead to a buildup of disease underneath the thatch and will cause "clumpiness," especially in tall fescue and orchardgrass.
Phosphorus and potassium should also be applied as needed according to the type of pasture. The timing of the application is not critical.
Periodic Soil Testing
Pastures should be soil tested about every 3 to 4 years to determine the need for additional lime and fertilizer. To maintain legumes in the pasture, the soil pH, phosphorus, and potassium levels must be kept at recommended levels for the species present. For example, clovers in Kentucky require a soil pH of 6.4 to 6.8, soil P (phosphorus) of 60 lb/A, and soil K (potassium) of 300 lb/A.
Weed Management
The best weed control in pastures is a strong, actively growing stand of grass. Fertilization (especially nitrogen), timely mowing, and good grazing management will also help keep weed pressure down. Herbicides are available for pasture use, but there are often trade-offs in their use. For example, 2,4D and other herbicides labeled for use on pastures will control broadleaf weeds but will also kill or severely stunt any clover present. Herbicide labels often require that horses be removed from a treated pasture for some specified length of time after spraying. (For some pull-off times for herbicides, see AGR-172, Weed Management in Grass Pastures, Hayfields, and Fencerows).
A properly managed pasture that is not overgrazed and is well fertilized should not allow weeds to predominate. However, if this does occur, apply appropriate herbicides in the weedinfested areas. Always read and follow herbicide label recommendations.
Source: University of Kentucky