Increasing Pasture Legume Content

There are a number of advantages to including a significant level of legume content in pastures. Legumes provide nitrogen, improve yield and increase forage quality. The most common legumes used in Ontario pastures are alfalfa, white clover, trefoil and red clover.
Productive pastures require regular maintenance. Rotation is one very effective way to improve pasture productivity. Improving the species mix in the pasture is also important. There are many advantages to including legumes:

• Nitrogen provided to the soil by legumes encourages grass growth as well as supporting the legume growth.
• Legumes have more consistent production during the mid-summer period. Some of the legumes, particularly alfalfa and trefoil, are deep-rooted and have better tolerance for the warm, dry conditions generally experienced in July and August. Grasses grow well during May and June, but July and August production is typically reduced.
• Legumes hold their feed quality longer than grass species, so pasture quality is more consistent throughout the summer grazing season.

Alfalfa Establishment
Alfalfa in the most productive of the legume species, but also has several drawbacks. Establishment of alfalfa requires excellent seed-to-soil contact and very little competition during the seedling stage. Most pastures with a significant level of alfalfa are established through conventional seeding, either planted into a tilled seedbed or no-tilled into a killed sod.

Frost Seeding Clovers & Trefoil
Clovers and trefoil can be established in a manner similar to alfalfa, or they can be frost seeded or over seeded into the pasture. In an established pasture, this is the easiest and likely the best option to increase the legume content. Frost seeding is done by broadcasting seeds on frozen ground in late winter or early spring. The best success has been reported with white clover, red clover and trefoil using this method.

The generally accepted seeding rate is 1-3 lbs of seed per acre, although there are no hard and fast rules as to the amount. White clover is often frost seeded at 1 lb/acre, trefoil at 2-3 lb/acre and red clover at 3-5 lb/acre.

The seed should be broadcast when the ground is still frozen. The freeze-thaw action during the spring will help to establish seed-to-soil contact. This broadcasting can be done with a broadcast seeder on an ATV or snowmobile.

Results are not always evident in the first year, but by the second season you will generally see an increase in the legume content of your pasture. White clover and trefoil can also be mixed in the livestock mineral/salt during the grazing season. The livestock will then spread the seeds across the pasture with the manure. This method may not be as effective but it is low cost and easy.

For further information refer to:
www.omafra.gov.on.ca/english/crops/field/news/croptalk/2007/ct-0307a8.htm
www.omafra.gov.on.ca/english/crops/facts/98-071.htm