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Topics : Species and Forage Variety Trials : Species Fact Sheets : Prairie Grass

Species: Prairie Grass

Additional prairie grass Information via the Forage Information System (FIS)


Prairie Grass Harvest Management

After spring seeding, prairie grass can be grazed after 50 to 70 days or harvested for hay after 80 to 110 days, depending on climatic conditions. Grazing the initial harvest after spring seeding will stimulate the formation and development of new shoots. Even though prairie grass roots develop faster than smooth bromegrass or tall fescue roots, make sure the grazing animals do not pull the young plants out of the ground.

If the seedling growth of prairie grass is harvested for silage or hay, fewer new shoots will develop and the stand will have reduced ground cover and a bunch type appearance. Prairie grass yield from the first harvest after seeding will be similar to that from smooth bromegrass but less than that from tall fescue. Grazing in the fall after a summer seeding is not recommended.

In established prairie grass stands, delaying the first spring harvest will reduce recovery rate and lower the yield potential of the next cutting. Under normal weather conditions, about 25 to 30 days of regrowth is sufficient between harvests. This period is a good balance between yield and quality of prairie grass. Generally, by this time new shoots have developed at the base of the plant and harvesting or grazing will allow more light to reach the shoots and stimulate their growth. A growth period of approximately 50 days in mid-summer will allow the prairie grass seed heads to mature and drop seed during August. This will thicken up the stand the following year.

Prairie grass's ability to grow at cool temperatures makes it ideal for late fall or early spring grazing. Fall yields of nearly 3.5 tons per acre are possible. It persists best when managed so that monthly harvests are made during the fall. In addition, spring yield and shoot density increase when multiple harvests are made in the fall. Harvesting only once in the fall (November) caused 98 percent of the of the basal shoots (source for growth the following spring) to winter kill. However, when prairie grass was harvested or grazed 3 times during the fall only 35 percent of the basal shoots winter killed. Compromise is needed with regard to fall harvesting because late fall grazing will slightly reduce prairie grass vigor the following spring and restrict its use as an early spring grazing source.

Prairie grass should not be cut or grazed below a 3 inch stubble height because regrowth energy reserves and buds for plant regrowth are contained in this region. Cutting or grazing below this height will weaken the plant and delay regrowth. Yields of nearly 7 tons per acre have been achieved when harvesting prairie grass for silage.

Prairie grass is an ideal grass for grazing systems because of its potential for early spring and fall growth. Its spring growth offers the opportunity for earlier spring grazing and its fall growth can effectively extend the grazing season by as much as two months over traditional cool- season grass species. In addition, since seed heads are palatable, it is not necessary to mow off the seed heads that remain after grazing.

Prairie grass persists better under rotational grazing than continuous grazing management. It will not withstand overgrazing, especially when it is under stress of excessively wet or dry conditions.

The quality of prairie grass is not as strongly affected by time of harvest as other cool-season grasses. Digestible dry matter intake (DDMI) is greater for Matua prairie grass than orchardgrass. When harvested on May 21, Matua had 25 percent greater DDMI than orchardgrass. This difference increased to 35 percent when harvesting one week later. Prairie grass may contain lower levels of trace elements than other grasses. Inclusion of a legume in the mixture with prairie grass, or providing trace elements to animals consuming primarily prairie grass will eliminate potential problems.