Grazing management is the most neglected aspect of maintaining a productive pasture that contains the desired species. Without proper grazing management, the benefits of fertilization are not realized and invasion of weeds is accelerated. For information on grazing practices, see “Grazing Management,” below.
A soil test is the best guide for proper fertilization. In the absence of a soil test, refer to the typical plant nutrient recommendations listed in Table 1.2-5.
The desired production level and species present in the pasture determine the fertilization of a pasture. Maintaining a pH above 6.0 is necessary to keep legumes in the pasture. If legumes constitute greater than 30 percent of the pasture, then fertilizing with nitrogen is not recommended because the legume contributes adequate nitrogen through nitrogen fixation. Fertilize these pastures annually with phosphorus and potassium. If the pasture contains less than 30 percent legume, then fertilize as if the legume were not present.
Nitrogen is extremely important for grass production. Depending on the grass species, 150 pounds of nitrogen per acre, split and applied at least three times during the year—50 to 60 pounds per acre in early spring when the grass first greens up and 50 pounds per acre in early and late summer—may be needed to maintain production.
Manure can be used in place of fertilizers to supply plant nutrients, but this can lead to potential problems in a grazing situation. Grasses that have been exposed to manure generally are less palatable, which may reduce animal intake. In addition, adding manure to a pasture increases the risk of parasite cycling in the grazing animals.
A properly maintained pasture promotes a vigorous sod that is highly competitive with most weeds. Insects and diseases can be expected to be the same in pastures as for plants managed for hay or silage. Refer to the “Pest Management” section of this guide for more information.