Renovating Pasture to Improve Productivity

Productivity of permanent and naturalized pastures could be greatly improved by adequate management practices, such as proper fertilization, appropriate grazing management and a change in the forage species present in the current pasture systems.

Good and thoughtful planning could do half of the job of pasture improvement programs and improve production more than twofold, depending on the soil properties and the current pasture conditions. Inputs needed for pasture renovation programs include partial or complete destruction of the existing sods, fertilizer and lime, weed control and use of superior species and cultivars. Renovation, or improvement, of pastures could be greatly enhanced by seeding to establish or reestablish desired forage plants without an intervening crop.

Renovation often involves the introduction of legumes into the perennial grass pastures, and interseeding is the introduction of a more productive legume or grass into an existing sod. Production of a low-yielding pasture can be doubled or tripled with this method.

Introduction of legumes into perennial grass sods often enhances the productivity and profitability one step farther by improving annual dry matter production more than twofold by bettering forage quality and soil health, by eliminating or minimizing nitrogen fertilizer and by decreasing bloating problems compared to legumes when grown alone.

Red clover is more easily established in the pastures than most legumes, as it produces high yields the year of seeding, but it also does not normally persist more than three years under grazing. Species like birdsfoot trefoil are slow to establish but can provide longer-lived stands. Cool-season grasses or legumes are often interseeded into thinned pasture to increase productivity and profitability.

Complete renovation through reseeding of pastures can be done either by conventional seeding or by no-till drill. No-till technology enables pasture renovation without plowing or disking existing pastures through management and use of herbicide that suppresses existing sods. When properly managed and adjusted, no-till drill technology can be effectively used to place the forage seeds at the proper depth and to ensure good seed-to-soil contact. Success of this technique has been reported in humid regions as well as western rangelands.

Pre-planning is important for successful pasture renovation. For spring pasture renovation, preparation should start in the previous fall through close grazing or clipping to control existing vegetation, a treatment that helps in reducing surface residues that would shade new seedlings.

Before spring application of contact herbicide to suppress existing sods, it is recommended to allow some accumulation of green foliage to obtain effective suppression with an herbicide. The herbicide can be broadcast sprayed uniformly over the entire surface, or a band can be applied, if an adequate stand of desirable grasses is present, and if the renovation is being made primarily for the introduction of legumes.

Good planning is the key for successful pasture renovation, and the planning needs to be made at least a year ahead. Pasture renovation depends on successful stand establishment and management, and interseeding/reseeding and no-till pasture renovation offer unique opportunities for improving pasture productivity, quality and profitability.

It is essential to know the key factors responsible for successful pasture renovation, and site selection, species and cultivar selection, planting method, fertilization, liming and weed management are among the most important factors to be considered.

Anowar Islam is a UW assistant professor and the UW Cooperative Extension Service Forage Agroecologist in the Department of Plant Sciences in the College of Agriculture and Natural Resources. He can be reached at 307-766-4151 or mislam@uwyo.edu.