Forage and weed species identification crucial for stressed fields

Plant identification skills are critical for assessing stressed hayfields and pastures.

Hayfields and pastures across Michigan suffered severe drought conditions in 2012. For some farms, this was the second or even third year of low-moisture growing conditions. The unusually early spring thaw of 2012 followed by freezing weather added to plant stress, especially for more vulnerable legumes. Winter kill and drought resulted in reduced productivity and conditions of many hayfields and pastures. Improved soil moisture conditions in the fall of 2012 relieved drought stress in many locations, but surviving plants can’t bounce back immediately if badly stressed and damaged by adverse environmental conditions; it takes some time. In fields where there was significant die-out of forage plants, weeds will be filling gaps.

These stressed fields need careful examination and assessment as early as possible in 2013. The ratio of desirable forage species to weeds should be considered. If there are more weeds than forage species (as percent of ground cover), then replacement of the stand should be considered. If desirable forage species still appear to be dominant, then planning for stand improvement may be the best choice. A thorough evaluation of forage stands is best done in early summer and the early season seeding window will be past. Interseeding or frost seeding with an appropriate species and variety next year is an option to improve stands if needed.

A key skill in determining the condition of a forage stand is plant identification. People growing mixed forages should be able to identify grass and legume species. More common legumes include alfalfa, white clover, red clover, alsike clover and birdsfoot trefoil. A few others of interest are sweetclover, ladino clover, hairy vetch and falcata alfalfa (yellow-flowered). Forage grasses common in Michigan hayfields and pastures include orchardgrass, timothy, tall fescue, smooth bromegrass, Kentucky bluegrass and perennial ryegrass. Other forage grasses include reed canarygrass and meadow brome.

An excellent internet resource for brushing up on forage species ID before spring arrives is Purdue University Agronomy Extension’s Forage Identification Pages. Another great way to improve forage species ID skills is to attend pasture walk educational events sponsored by Michigan State University Extension. These events are scheduled during the growing season and occur in various locations around the state. To learn when these walks are scheduled, contact MSU Extension grazing educator Jerry Lindquist to receive the Great Lakes Grazing Newsletter electronically free of charge.

Of course, there a lot more weed species than forage species. The ability to identify weeds and rattle off their names can really impress your neighbors, and can be a highly valuable skill when assessing the condition of new and established stands of perennial forage. If the plant you see is not one you want, then it’s a weed. You can refresh yourself on weed ID and control before evaluating your forage stand by visiting the MSU Weed Science website and MSU IPM Program’s Identifying weeds in field crops website.

For more information, contact Jim Isleib, U.P. crop production educator, at 906-387-2530.

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