Originating in the Middle East and becoming popular in North America after 1850, alfalfa is now the highest-yielding perennial forage legume grown in the country. It also is one of the most popular crops grown for pasture in Illinois.
But why grow alfalfa in Illinois when you can produce 150 bushels per acre of corn? The answer for many growers is simple: for the protein and energy in alfalfa.
For instance, 10 tons of high-quality alfalfa hay contains approximately 4,000 pounds of protein, comparable to 760 bushels of corn or 160 bushels of soybeans. In energy, 10 tons of alfalfa hay provides 10,000 pounds of Total Digestible Nutrients (TDN), which equals 220 bushels of corn, or 25 tons of corn silage.
But not only is alfalfa unsurpassed in nutritional value, it offers versatility because it can be fed as hay, haylage, pasture, green chop, wafers, and pellets.
No other feed nutritionally performs so well with beef, dairy, swine, poultry, and horses. Although bloat in ruminant animals often is associated with alfalfa pastures, it is not an insurmountable problem. The bloat hazard can be reduced or essentially eliminated by balancing soil fertility, including grasses in mixtures with alfalfa, maintaining animals at good nutritional levels, and using bloat-inhibiting feed amendments.
In addition, alfalfa requires rotational grazing in pastures. With good grazing management and fertilization, alfalfa will persist four to six years in most pastures.
The second most important hay and pasture legume in Illinois is red clover. It does not have the yield potential of alfalfa under good production conditions, but it can persist in more acid soil conditions, under wetter soil conditions, and under more shade than alfalfa.
Red clover is physiologically a perennial, but root and crown diseases limit its life to about two years. New varieties, such as Arlington, Kenstar, Redland, and some privately developed varieties, have increased resistance to these diseases and are expected to be productive for at least three years.
Red clover also does not have as much seedling vigor or as rapid a seedling growth rate as alfalfa. Therefore, red clover does not fit into a spring seeding without a companion crop program as well as alfalfa does.
Because red clover has more shade tolerance at the seedling stage than alfalfa, it is recommended for most pasture renovation mixtures where there will be shading from existing grasses.)
(For information on other legumes, see these additional descriptions.)