Adding legumes to Missouri pastures
Many Missouri pastures have adequate grass stands but lack legumes. Where soils are suitable, adding legumes to existing grass pasture is one of the most cost-effective ways to improve pasture productivity and animal performance. In most cases, establishing legumes costs less than supplying equivalent nitrogen through fertilizer.
Legumes are well known for fixing nitrogen for themselves and companion grasses, but their benefits extend far beyond nitrogen alone. Grass-legume pastures typically support higher animal gains, improved reproductive performance, and lower overall pasture costs.
Benefits of including legumes in pastures
Well-managed legumes can:
- Increase average daily gain and weaning weights
- Improve cow conception rates
- Increase protein production per acre
- Reduce the risk of grass tetany
- Improve overall herd health
- Provide higher-quality forage and hay
- Supply nitrogen to both legumes and companion grasses
- Boost summer forage production during the “summer slump”
- Reduce dependence on purchased nitrogen fertilizer
Persistence and limitations
Pasture improvement with legumes is never permanent. Even under good management, legumes gradually decline and must be re-established periodically. Drought is especially damaging to shallow-rooted species such as ladino, alsike, and red clover.
Legumes are commonly lost due to overgrazing, inadequate fertility, poor soil pH, excess moisture, drought stress, disease, insect pressure, or improper fertilizer use. Most failures are directly linked to management.
The good news is that legumes can be successfully established into existing grass pasture without plowing and without sacrificing an entire year of forage production.
Preparing the pasture
Broadleaf weeds should be controlled before renovation begins. Herbicide applications are usually most effective when made in spring or summer prior to legume establishment. Always check grazing and reseeding restrictions on herbicide labels.
Successful establishment depends on temporarily suppressing grass growth so young legume seedlings can access light, moisture, and nutrients.
Methods for establishing legumes in grass pastures
Method 1: Frost Seeding with Grazing Management
This is the most common and lowest-cost method.
- Overgraze pastures in fall and early winter to weaken grass competition.
- Apply lime, phosphorus, and potassium as recommended by soil tests. Avoid nitrogen, which stimulates grass growth and suppresses legumes.
- Broadcast legume seed in January or February so freeze–thaw cycles work seed into the soil. February seedings generally have greater success than April seedings.
- Graze aggressively in early spring to remove fast grass growth and allow legumes to establish roots. This usually requires high stocking density for short durations. Grazing is far more effective than clipping.
Method 2: Partial Pasture Disturbance
- Disturb 40-50% of the sod in late fall or early winter using light tillage or aeration.
- Broadcast or drill seed into the opened sod during winter.
- Avoid nitrogen fertilizer.
- Control early grass growth with grazing or clipping.
Method 3: Chemical Suppression and No-Till Seeding
- Suppress grass growth with a labeled herbicide rather than tillage.
- Seed legumes using no-till drills, grassland drills, zip seeders, or modified corn planters.
- When using planters, narrow effective row spacing to 10-12 inches and place seed shallowly ahead of press wheels.
- Paraquat has historically been used as a contact herbicide during the growing season (early spring or late summer). Rates of 1-2 pints per acre are typically effective. Excessive rates can over-suppress grasses and allow weeds to invade, reducing seedling survival.
Always follow current label directions and safety requirements when using herbicides.
Soil fertility considerations
Soil testing is the first and most critical step. Test soils well ahead of seeding so lime and nutrients can be applied in time.
- Lime is essential for legume establishment. Benefits move slowly through the soil profile, so incorporate lime if applying more than 2-3 tons per acre.
- Most legumes require a soil pH of at least 5.5, with pH 6.0 or higher preferred.
- Phosphorus is especially important at establishment. Apply if soil tests are below medium.
- Potassium is less critical during establishment but is essential for long-term persistence.
- Do not apply nitrogen when establishing legumes into grass sods.
Time of seeding
Timely seeding is critical, especially when sod is not disturbed.
Frost seeding in January or February often produces excellent stands. While late freezes can occasionally damage seedlings, late seeding is far riskier. Poor soil contact and summer stress frequently result in seedling failure.
Seeding quality, species selection, and rates
Always use certified seed to ensure varietal purity, vigor, and performance. Single species are usually easier to establish and manage than mixtures, although limited mixtures can be useful in specific situations (such as wet soils).
Match legumes to grasses:
- Birdsfoot trefoil and alfalfa establish more easily with orchardgrass, timothy, or bluegrass.
- Ladino and red clover are better suited to tall fescue due to their aggressive seedlings.
- Dense fescue sods may be the most difficult environments for establishment.
Recommended seeding rates (pure live seed)
Alfalfa
- 10 lb/acre broadcast on undisturbed sod
- 8 lb/acre broadcast on tilled soil
- 6 lb/acre drilled
Ladino clover
- 1.5 lb/acre broadcast on undisturbed sod
- 1.0 lb/acre broadcast on tilled soil
- 0.5 lb/acre drilled
Red clover
- 10 lb/acre broadcast on undisturbed sod
- 8 lb/acre broadcast on tilled soil
- 6 lb/acre drilled
Birdsfoot trefoil
- 8 lb/acre broadcast on undisturbed sod
- 6 lb/acre broadcast on tilled soil
- 4 lb/acre drilled
Annual lespedeza
- 25 lb/acre broadcast on undisturbed sod
- 20 lb/acre broadcast on tilled soil
- 15 lb/acre drilled
Always inoculate legume seed with the correct rhizobia. Moisten seed before adding inoculant; dry mixing alone frequently results in poor nodulation and stand failure.
Legumes commonly used in Missouri pastures
Ladino clover
Ladino is one of the easiest legumes to establish and produces high-quality forage and abundant nitrogen. It performs best on fertile, well-limed soils. Drawbacks include higher bloat risk and reduced summer production during drought.
Red clover
Red clover establishes easily, tolerates a wide range of soils, and has moderate drought tolerance with lower bloat risk than ladino or alfalfa. Most stands persist two to three years, though newer varieties with improved persistence are extending its usefulness.
Alfalfa
Alfalfa provides excellent quality and drought resistance but requires high fertility, good drainage, and careful grazing management. Insect management, especially alfalfa weevil, often limits its use in pasture systems.
Birdsfoot trefoil
Birdsfoot trefoil is highly palatable, non-bloating, and persistent under proper management. It tolerates a wide range of soils and is relatively drought tolerant. However, it establishes slowly and must be managed to encourage reseeding, particularly in September.
Sweet clover
Sweet clover is a biennial species best suited to very droughty soils. It requires frequent reseeding and can suffer from sweet clover weevil pressure. Its use is limited but can be valuable in challenging environments.
Alsike clover
Alsike performs best on wet or poorly drained soils but is short-lived on uplands. It produces little summer regrowth and is best used as a specialty legume, often mixed with small amounts of ladino.
Annual lespedeza
Lespedeza tolerates low fertility and acidic soils, produces good animal gains, and does not cause bloat. It performs poorly at high pH and relies on reseeding for persistence. Variety selection is important to avoid disease and poor seed set.
Managing new seedings
Graze lightly in spring, then rest the pasture for four to five weeks. After rest, use rotational grazing through late summer.
Avoid grazing new seedings from early September until cold weather begins. Overgrazing during the establishment year is one of the most common causes of failure.
Summary
Adding legumes to existing pastures is one of the most economical ways to increase forage quality, animal performance, and long-term pasture productivity in Missouri. Success depends less on the method chosen and more on soil fertility, timing, and grazing management during establishment.