Springtime is a Good Time to Plant Alfalfa in Kansas 4/6/05

MANHATTAN, Kan. – Warmer April and early May weather signals a good time to plant alfalfa in Kansas, said Kansas State University agronomist Jim Shroyer.

"April is the best time to plant spring alfalfa, although it can be planted into May as long as it’s going into irrigated fields," said Shroyer, who is a crop production specialist with K-State Research and Extension.

K-State Agronomist Offers Alfalfa Planting Tips

MANHATTAN, Kan. – Since April through early May is a good time to plant alfalfa, Kansas State University Research and Extension agronomist Jim Shroyer shared these tips:

* Take a soil test. Alfalfa thrives on well-drained soils with a pH of 6.5 to 7.5.

* Inoculate the seed to help ensure the nitrogen fixation necessary for optimum production.

* Plant in firm, moist soil. This can be accomplished with no-till.

* In general, plant seed 1/4 to 1/2 inch deep. But never plant less than 3/4 inch deep in sandy soils unless the field is irrigated.

* Use the right seeding rate. Plant 8 to 12 pounds of seed per dryland acre in the west, 12 to 16 pounds per dryland acre in central and eastern Kansas, and 15 to 20 pounds per irrigated acre in all soils.

* Check for herbicide carryover if planting no-till alfalfa into corn, sorghum or soybean residue.

* Choose varieties that can resist phytophthora root rot, bacterial wilt, fusarium wilt, verticillium wilt, anthracnose, pea aphid, spotted alfalfa aphid, and other diseases and insects.

“Pest resistance contributes to stand longevity,” Shroyer said.

* Plant certified, treated seed.

* Plan to use herbicides, if necessary.

More reliable moisture and less variation in the weather make planting alfalfa in the spring less risky than planting in the late summer or fall, Shroyer said. The latter, however, increases the amount of forage produced the first year.

Because alfalfa is a five- to seven-year investment, he recommends that growers have their soil tested to determine if phosphorus needs to be added: “For every ton of alfalfa removed from a field, 10 pounds of phosphorus are removed. It’s something to keep in mind when considering planting alfalfa.”

Choosing a well-adapted variety with a fall dormancy rating of 3 to 5 is best, Shroyer said, adding that disease resistance is also important.

"Fall dormancy ratings of 3 to 4 are best for the northern part of the state, and 4 to 5 are best for southern areas," the agronomist said. "The lower the number, the earlier the variety goes into dormancy and the less productive it is in the early fall."

Shroyer also recommends as little seedbed preparation as possible, because minimizing tillage can decrease planting costs and help maintain soil moisture levels. He encourages growers to consider no-till when preparing to plant alfalfa. One alternative is to plant alfalfa seed into the stubble of last year’s row crop, such as corn or soybeans.

"If there are no weeds growing, the ground is perfect for planting without tillage. The crop residue provides protection from erosion. By not tilling, this method reduces moisture loss, saves time and cuts costs," he said.

"Know the herbicide program in the previous crop and be wary of carryover that could damage the alfalfa," Shroyer said. "Pay attention to the label because there may be rotation restrictions."

Herbicides applied to small grain crops that may have detrimental carryover to alfalfa include Glean, Finesse, Amber, Ally, Ally Extra, Maverick, Olympus, Rave and Peak, said K-State Extension agronomist Dallas Peterson. Spirit, Equip, Steadfast, Peak and Atrazine-containing products used on row crops the previous year also can carry over and damage newly-planted alfalfa.

Peterson, who is a weed specialist, suggests that farmers consider a herbicide application if they anticipate a weed problem.

Treflan can be used as a pre-plant incorporated treatment in conventional tillage for control of annual grasses and pigweeds, he said. However, Treflan will not control large-seeded weeds, such as velvetleaf and cocklebur. It also can sometimes reduce alfalfa emergence if the alfalfa was seeded a little too deep and if cool, wet weather occurs following planting.

Post-emergent herbicides for alfalfa include Buctril, Butyrac 200, Poast Plus, Select, Raptor and Pursuit. Buctril and Butyrac 200 will control certain broadleaf weeds, while Poast Plus and Select are labeled for grass control. Raptor and Pursuit can control both broadleaf and grass weeds in alfalfa.

“Read and follow all label directions when using any pesticide,” Peterson said.

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.