Farmers planning to plant Roundup Ready alfalfa this year need to hurry.

A U.S. District Court in San Francisco issued a preliminary injunction order March 12, finding fault with the regulatory process the U.S. Department of Agriculture used in approving the Monsanto product.

Pending further hearings, the court injunction stopped sales of Roundup Ready alfalfa seed March 12. Growers who had bought the seed earlier may still plant it - IF they can do so by March 30.

"Planting as early as March is by no means usual in Kansas. Still, it shouldn't cause any stand problems," says Jim Shroyer, Kansas State University agronomist.

K-State recommends no-till or reduced-till as the best approach to planting alfalfa, he said. Either offers a firm soil surface, helps maintain soil moisture, saves time, and reduces planting costs.

"One problem with having a narrow planting window, though, is that you don´t want any weeds growing when you seed alfalfa," says Dallas Peterson, weed scientist with K-State Research and Extension. "At the same time, you have to be certain that no herbicide carryover from a previous crop could injure the emerging plants."

Another potential delay is alfalfa's nutrient needs, he says. Producers must inoculate alfalfa seed to help it achieve the nitrogen fixation needed for top production. They also need an already-completed soil test to determine which fertilizer and/or other soil amendments to apply.

"Alfalfa does best when the soil pH ranges from 6.5 to 7.5. In soils with a lower pH, alfalfa can grow thin and weedy, so applying lime before planting can pay big dividends," Shroyer says. "Plus, alfalfa is a big phosphorus user, removing about 10 pounds of P with every ton of alfalfa harvested.

"Past research in Kansas has shown that applying and incorporating a P fertilizer will result in large yield increases. Even in a no-till situation, a surface-applied P fertilizer can have a long-term, beneficial effect on productivity. First, however, you need that soil test to know how much to apply."

Roundup Ready alfalfa is resistant to the effects of Roundup, a popular weed-controlling herbicide.