Agronomy Guide
COOPERATIVE EXTENSION SERVICE. PURDUE UNIVERSITY. WEST LAFAYETTE, INDIANA (PASTURE) AY-251

improving Pastures by Renovation
K. D. Johnson, C. L. Rhykerd, and J. M. Hertel, Department of Agronomy and K. S. Hendrix, Department of Animal Sciences, Purdue University
In Indiana, pastures are generally relegated to land that is too steep and rocky for row crops. The soils tend to be shallow, low in fertility and droughty. The dominant plant species are often Kentucky bluegrass, tall fescue and weeds. The result of this combination of conditions is usually low yields of low quality forage.
One of the best ways to improve both forage yield and animal performance on these low-producing grass pastures is to periodically renovate them. Pasture renovation means “renewing" a pasture by the introduction of desired forage species into present plant stands. It usually involves partially destroying the sod, liming and fertilizing according to soil test, seeding a legume or legume-grass mixture, and controlling weeds.
BENEFITS OF LEGUME-RENOVATED PASTURE
Research and farmer experience show that introducing legumes into Kentucky bluegrass or tall fescue sods produces the following benefits:
•	Elimination of the need for nitrogen fertilization.
•	Better seasonal distribution of forage. (Legumes are more productive in mid-summer than cool-season grasses.)
•	Increased forage protein content and quality.
•	Improved forage digestibility and palatability.
•	Higher mineral concentrations (especially calcium and magnesium), which help prevent animal health problems.
•	Improved livestock performance, such as daily gain, milk and wool production.
•	Improved beef breeding performance. (Legumes have been shown to reduce sheep breeding performance because of estrogenic compounds.)
Pasture renovation experiments in Ohio and Indiana illustrate the degree of improvement from the introduction of legumes into low-producing grass sods. An Ohio State University study (Table
1)	revealed significant increases in cow-calf carrying capacity by renovating a permanent bluegrass pasture. Some improvement was made simply by adding a better forage grass. Further improvement was achieved by increasing soil fertility. However, the greatest improvement resulted from growing either a mixture of alfalfa and orchardgrass or a well-fertilized orchardgrass, both of which tripled animal carrying capacity as compared to the unfertilized bluegrass pasture.
A recent Purdue University experiment (Table
2)	further supports two of the Ohio findings, suggesting they be carefully considered when making pasture renovation decisions. One is that some grass species are better than others as pasture for cow-calf herds. (Compare the daily gains and conception rates for herds on orchardgrass vs. tall fescue receiving the same amount of nitrogen.) The second finding is that seeding a legume into a tall fescue pasture gives better cow-calf production results than merely fertilizing the tall fescue pasture with nitrogen and gives similar results to N-fertilized orchardgrass. (Again in Table 2, compare animal performance on the tall fescue-clover mixture vs. tall fescue alone receiving N fertilizer.)
MAJOR PROBLEMS IN PASTURE RENOVATION
Pasture renovation needs to be done on a regular basis. The reason is that legumes, as compared to grasses, tend to be short-lived in a pasture. In fact, they will disappear rather quickly in the face of such “adversities” as lime, phosphorus and potassium deficiency, disease and insect