Description:

• Alsike Clover (Trifolium hybridum) flowers are pink to white, and are much smaller than red clover
• The stems do not terminate in a flower as they do in red clover.
• Approximately 653,000 seeds per pound, 60 pounds per bushel

Management considerations:

• Alsike clover is used for hay, pasture, and green manure.
• It prefers silty clay loams, and does not tolerate droughty sites
• Tolerates wet or acid soils better than other clovers or alfalfa
• Alsike is usually seeded with grasses due to lodging potential
• Less productive but more disease resistant than red clover
• Alsike clover is associated with photosensitization in horses which causes a negative reaction to light, and with big liver syndrome which may cause liver damage.

Optimum Planting Dates:

• In Minnesota, alsike clover can be seeded from early spring to
  August 10.
• Alsike clover can be frost seeded into existing grass pastures in early spring.
• The freeze-thaw cycle will incorporate the seed into the soil.
• It can also be no-till seeded into existing grass pastures.

Seeding Recommendations:

• To ensure adequate root nodulation for nitrogen fixation, clover seed should be inoculated with Rhizobium bacteria.
• Plant 1 - 3 lbs per acre in a mix or 5 - 8 lbs/acre as a plowdown.
• Do not plant deeper than 1/4 inch when seeding. Press wheels or cultipacking will improve the seed-soil contact and the chances of obtaining a good stand. To obtain a proper seeding depth, the seedbed should be firm.

Fertilization: (Consider a soil test and please contact your fertilizer professional for your specific needs):

• As a legume, alsike clover fixes atmospheric nitrogen with Rhizobium bacteria in its root nodules so additional nitrogen fertilizer is generally not required.
• Be sure the seed is treated with the proper inoculant before planting. If your soil is very acidic (pH 5.0 or lower), nodulation may be reduced and extra nitrogen may be necessary.
• Consult Tables 3 and 4 on this website for Phosphorus and Potash recommendations.
• Pre-plant fertilize according to a soil test.

Weed and Disease Control: (This is not intended as a recommendation or endorsement of any specific product but as a list of possible controls. Please contact your chemical professional for your specific needs and always read and follow label directions):

• Select fields that have relatively good weed control, as clover seedlings do not compete well with established weeds.
• Maintaining dense, competitive forage is important in preventing weed problems.
• Regular mowing can kill or suppress annual and biennial weeds. It can also suppress perennials and help restrict their spread.
• There are few herbicide treatments available for mixed grass-legume combinations. Spot spraying may be the best option for scattered weed infestations.

Improving Pasture by Frost Seeding

Pasture Management - University of MN

Description:

• Tall-growing biennial legume (some annual varieties are available)
• Quite winter-hardy
• Most drought-tolerant of forage legumes
• Often used for livestock grazing or hay, a Nitrogen plowdown cover crop, soil builder, or a beneficial insect attractant.
• White blossom sweet clover is often used by beekeepers

Management considerations:

• Does well in the same soils as alfalfa, i.e., well-drained with near neutral pH
• Most nitrogen and organic matter production occurs in the second year
• Scavenges phosphorus, potassium and micronutrients from that are unavailable to other crops
• Avoid mowing or grazing of sweetclover in the six- to seven-week period prior to frost
• For best results, kill sweetclover in the second year when stalks are 6 to 10 inches by mowing, cultivating or disking once it reaches late bloom stage
• Produces hard seed that can lie in soil for 20 years
• Use caution when feeding sweetclover hay or silage. Sweetclover hay stored too wet will mold and may cause Sweetclover Bleeding Disease which can cause animals to bleed to death from slight wounds or internal hemorrhages.

Optimum Planting Dates:

• Spring is the best time to plant sweetclover because moisture conditions are most favorable for rapid seed germination and seedling establishment.
• Sweetclover grows slowly for the first 60 days after planting.
• Unlike alfalfa and other clovers, late summer and fall seedings are not recommended because sweetclover must develop an extensive root system and store energy reserves during the fall growth period.
• If a late season seeding is necessary, plant at least six weeks before frost so roots can develop enough to avoid winter heaving.

Seeding Recommendations:

• To ensure adequate root nodulation for nitrogen fixation, clover seed should be inoculated with Rhizobium bacteria.
• In the Corn Belt, drill 8 to 15 lb/acre or broadcast 15 to 20 lb/acre, using the higher rate in dry or loose soils or if not incorporating.
• Plant 1/4 to 1/2 inch deep in medium to heavy textured soils (slightly deeper in sandy soils). Press wheels or cultipacking will improve the seed-soil contact and the chances of obtaining a good stand. To obtain a proper seeding depth, the seedbed should be firm.
• Seeding too heavily can result spindly stalks and increase lodging which can lead to disease problems.
• Can be frost-seeded successfully.

Fertilization: (Consider a soil test and please contact your fertilizer professional for your specific needs):

• Sweetclover will fix nitrogen if inoculated properly.
• Primary fertilizer requirements are phosphorus and potassium. (Sweetclover will remove about 12 pounds of P and 50 pounds of K from the soil per ton of forage produced.)

Weed and Disease Control: (This is not intended as a recommendation or endorsement of any specific product but as a list of possible controls. Please contact your chemical professional for your specific needs and always read and follow label directions):

• Select fields that have relatively good weed control, as clover seedlings do not compete well with established weeds.
• No herbicides are labeled or approved for use on either seedling or established sweetclover.
• Maintaining dense, competitive forage is important in preventing weed problems.

Sweetclover Production and Management

Managing Cover Crops Profitably, 3rd Edition

Improving Pasture by Frost Seeding