Alfalfa Rotation Explained

After five years, alfalfa yields generally decline. So, most farmers take that field out of the crop for a year or more before replanting.

By Des Keller | Photos By Brett Deering

“There is a funny quirk to alfalfa, that it produces an autotoxin, a chemical that suppresses its own seedlings from developing nearby an alfalfa plant,” says Dennis Hancock, an Extension forage specialist at the University of Georgia and the supervisor of the Southeastern Hay Contest. “The bottom line is that the toxin creates a zone of about a yard around an alfalfa plant that prevents a new seedling from growing. And it takes about a year for that zone to dissipate.”

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Developed nearly 20 years ago by the University of Florida and the University of Wisconsin, relative forage quality (RFQ) offers a way to quantify an “apples-to-apples” comparison of the feed value of various grasses and legumes. There are two factors used in the RFQ measurement: total digestible nutrients (TDN), which is a measure of digestible energy, and a calculated estimate of dry matter intake (DMI).