Developing a fertility program for your forage crops may not be as simple as determining nutrient needs for row crops. In row crop production you apply nutrients with the simple goal of maximizing yield. While you would like to grow as much forage as possible, your real goal should be maximizing the utilization of the forage grown.
Before developing a fertility program for your cool season grass pasture and hay fields, it is a good idea to evaluate your current forage species and stand health. Evaluating your current forage inventory will help determine seasonal production and times of excess or shortages in forage production. The goal should be to increase forage production or availability when forage is typically short and to increase utilization of forages when excess growth occurs.
You can use fertilizer, specifically nitrogen, to promote growth to meet seasonal needs. Grasses respond well to nitrogen fertilizer. Each ton of fescue produced requires 40 pounds of nitrogen. The soil will supply some nitrogen to the plant. The goal becomes to provide additional nitrogen to promote growth when needed. You can use nitrogen to promote growth of fescue in the spring and late summer. Determining when and how much nitrogen to apply will depend on your specific goals and should be evaluated on a field-by-field basis.
In order to get maximum benefit from nitrogen applications, soil-test levels for pH, phosphorus and potassium should be within recommended ranges. Apply lime, phosphorus and potassium according to soil test results.
Stockpiling tall fescue for fall and winter grazing
Stockpiling is the practice of accumulating growth in the late summer and fall with the purpose of grazing the forage produced through the winter months. Nitrogen applications in early to mid-August will promote growth of tall fescue and increase total forage production. Target thick and healthy stands for nitrogen applications. It is best to graze or mow summer growth down to three inches before fertilizer applications.
Response to nitrogen fertilizer will depend on available moisture. Apply 40 to 60 pounds of nitrogen in early to mid-August for fall growth. Apply higher rates when excess forage is needed if moisture is adequate and yield potential is high.
In order to maximize forage utilization and return on fertilizer investment for stockpiled forage, cattle should be managed with controlled grazing. Strip grazing will reduce waste and maximize forage intake. Research conducted at the University of Missouri has demonstrated that stockpiled tall fescue maintains quality throughout the winter months.
Spring applications of nitrogen to promote growth of tall fescue
Spring nitrogen applications should be made to promote growth at the time of greatest forage need. If managing for hay or maximum tonnage, the nitrogen should be applied before grass greens up in early spring. Figure about 40 pounds of nitrogen per ton of growth desired.
If you have adequate forage early in the spring or can’t keep up with the early flush of growth, you can apply nitrogen after the first grazing cycle. Applying later in the spring will reduce overall tonnage but should extend the grazing season longer into the summer months.
Using fertilizer to promote forage growth to meet production goals and seasonal needs reduces waste and maximizes forage utilization.
Steve Cromley is senior staff agronomist for MFA Incorporated.