Many grazing-tolerant alfalfa varieties have been developed in recent years. As Kentucky farmers begin to make planting decisions, they will want to know which of these varieties will perform best under their particular growing conditions.

University of Kentucky agronomists have the answer based on more than four years of research to determine the varieties' tolerance to continuous, heavy grazing pressure as well as yields under the same environmental conditions.

"Kentucky is among the few states conducting grazing studies on varieties. This research is our farmers' best data to verify if the variety is grazing tolerant ," said Garry Lacefield, Extension forage specialist with the University of Kentucky College of Agriculture.

"Through these alfalfa trials, we have verified grazing tolerance under Kentucky growing conditions and identified varieties that can tolerate overgrazing without stand loss, compared to the standard hay-type alfalfas," said Jimmy Henning, Extension forage specialist. "The newer grazing-tolerant varieties also had much improved yields over some of the earlier varieties."

The variety trials were conducted under continuous heavy grazing pressure rather than the frequent clipping to simulate grazing in many other research projects.

In addition to grazing tolerance, farmers should consider some other factors when selecting alfalfa varieties, according to Henning.

"Farmers should use the results of these variety trials along with yield and pest resistance information to select the best alfalfa variety for their particular situation," he said. "We don't recommend that farmers allow alfalfa to be continuously grazed as we did in these variety trials. Even though several varieties had tolerance to continuous grazing pressure, overgrazing will greatly reduce yield and therefore the profitability of these varieties.

"Although we tested these varieties under continuous and heavy grazing pressure, we recommend careful and planned rotational grazing as the best management for alfalfa in a grazing program. Good management for maximum life would be to let the stand become completely established before grazing. Let livestock graze forage for seven days or less and then let the stand rest for 28 days before putting livestock back on it. Add any fertilizer or lime necessary. Take grazing livestock off the alfalfa from mid-September until November 1 to replenish root reserves."

Henning said variety trial results are available from most county Extension offices. This information also is located on the UK College of Agriculture's home page. The URL for this site is http://www.ca.uky.edu/agc/pubs/respubs.htm. The "Alfalfa Grazing Tolerance Variety Trial Report" is PR-415.