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Superintendent
David Davis
21262 Genoa Road
Linneus, MO 64653
Phone: 660 895-5121
FAX: 660 895=5122
Email: DavisDK@missouri.edu

Forage Systems Update
Vol 9, No. 2

Cool-season and Warm-season Grasses Together

One of the most challenging pasture mixtures to manage in the Midwest is cool-season grasses along with native warm-season tall grasses. The growth habits are very different, the relative palatability at certain times of the year are quite different, the required residual heights and rest periods are different, and, obviously, the seasons of growth are different. While the experience with continuous grazing or slow rotations is that these species are unlikely to occur in the same pasture, many producers have seen the tall grass component of their pastures increase with management-intensive grazing (MiG). A remnant population of native grasses actually exists in most long-term cool season pastures in the corn-belt region. If land has been extensively cropped in the past, native grasses is unlikely to develop without interseeding. From time to time, I am asked for a management guide for encouraging native tall-grass increase in cool- season dominant pastures without the use of tillage or chemicals. The following is a guide through the grazing season for encouraging warm-season grass development in existing cool-season pastures where a remnant population is observed.

All of these recommendations are based on the assumption that there are multiple paddocks in the grazing unit and length of grazing period and rest period can be varied as needed. The target paddocks should be some of the first paddocks grazed in the spring. Initial greenup is going to be composed entirely of cool season species. This early growth needs to be grazed fairly severely, leaving as little as two inch residual growth. In northern Missouri, this grazing usually takes place late-March to mid- April. Warm-season grass growth usually begins in late April or early May. A second grazing will need to be made as the native grass is just getting started. This second grazing is not as severe as the first, leaving 3 to 4 inch residual. Timing is early to mid-May followed by rest until mid to late June.

The two early grazings have slowed down cool-season growth and the mid-May to mid-June rest period has allowed the warm-season grass to reach target grazing height of 10 to 12 inches. The first grazing of the warm-season grass should leave at least 6 inch residual and be followed by at least 30 days of rest. The second warm-season grass grazing should occur late July to early August. Until the warm-season component has reached the desired level in the mixture, avoid grazing later than August 15. Regrowth should reach at least 10 to 12 inches before frost. A final grazing can be made after frost, but plan on leaving at least 6 to 8 inches of native grass stubble. This usually is not a problem as the cattle will prefer to graze the green cool-season material out of the mixture.

Not grazing the final growth and conducting a spring burn may accelerate the rate of warm-season grass increase in the sward. Three to five years of this management strategy will usually result in a significant native grass component in the mixture. The stronger the remnant population at the beginning, the greater the final native grass component will be. Combining severe winter grazing with spring no-till seeding of native grass can also help accelerate the process. With experience, most graziers learn how and when to adjust grazing practices to shift the mixture in whatever direction they choose. Repeatedly grazing every paddock to very short residuals will almost always keep the mixture predominantly cool-season species.

Jim Gerrish, Editor
GerrishJ@missouri.edu