Establishing alfalfa-grass mixtures
Alfalfa fields continue to dominate the forage landscape across Midwestern states. However, mixing an alfalfa variety with grass species to create hay fields is increasingly popular in Eastern U.S. dairy regions. The practice was popularized decades ago by beef producers.
While initial hay fields may have naturally evolved from grasses filling in areas of lost alfalfa plants, today’s production is much more intensively managed.
Keys to successful establishment
Forage production is a three- to six-year commitment, depending on a producer’s decisions, management practices and field rotations to benefit the farm as a whole system. This is unlike annual commodity crops, in which producers evaluate and select genetics and inputs each year.
Because of this expanded commitment, it’s important to recognize, understand and implement key management considerations.
The genetics of selected varieties and grass species to be mixed are critical to successful forage production. This first step to strong production must also include stand establishment, harvesting schedules, fertility and pest management considerations.
Alfalfa variety considerations
Having a productive stand over several years first depends on the mixture to be planted. The easy part is the alfalfa variety, which you can select based on proven University yields over locations and years.
Target and evaluate significant genetic traits such as tonnage, quality, winter hardiness, fall dormancy and pest resistances (insects and diseases). University of Minnesota alfalfa performance results.
Grass variety considerations
Producers commonly take the most time in deciding which grass specie(s) to mix with the alfalfa.
A common mistake is concentrating too long on which species to include instead of which variety. University of Wisconsin research shows that the grass specie has marginal effects on total season yield, but variety selection is crucial.
Orchardgrass, tall and meadow fescue and bromegrasses are dominant species to use in mixtures. Choose varieties of these grasses for:
Yield seasonal distribution.
Disease resistance focusing on rusts.
Producers often determine which grass species to include and then settle for whichever varieties are available with the nearest retailers.
Yet, few realize that more than 30 orchardgrass varieties are available and large genetic differences exist. This contributes to production success and failure, depending on needs and expectations.
Maximize the mixture by aiming to have 30 to 40 percent of the stand comprised of grasses. Focus on seeds per square foot planted rather than pounds per acre.
Seeding rate recommendations are generally accepted as 60 to 75 seeds per square foot. At the end of the first year, this results in a final stand of 30 to 35 plants in the same area to maximize yield.
A rule of thumb puts the alfalfa at 10 pounds per acre, which is 47 seeds per square foot with the remainder grasses. Adding a low rate of annual ryegrass at seeding will significantly add to first-cut yield, while providing additional early weed competition and soil erosion control.
Causes of failure
Seeding the hay mix is where many mistakes occur. Unfortunately, this can cause annual problems with yield, weeds and stand longevity.
While many planting methods and techniques can successfully establish the forage mix, three things are essential. Planting failures commonly are traced back to:
Poor seed-to-soil contact.
Seed placed too deep.
Soil pH problems not compatible to the mix created.
Strategies for success
Carefully select forage field locations understanding topography, drainage, soil types and pH. Match genetics and management to these factors.
Optimize seedbed preparations, including for soil moisture, firmness and residue management.
Check often to ensure your method is delivering the correct amount of seed, uniformly at a target depth of 1/4 inch. This is true regardless of equipment used. Larger equipment, faster planting speeds, varying soil types and residue are all complications in successful seed placement.
Over the years, many producers have found it’s much easier to correctly plant a field than try to renovate a poorly established one. It’s well-documented that a field requiring patching or seed supplementing will never perform as well as the initial seeding operation.
An essential consideration important to alfalfa-grass mixtures is cutting height.
Target a remaining height of 3 to 4 inches at harvest. This unharvested material is essential, as it serves as the photosynthetic base needed for regrowth and stand persistence over time.
Other considerations include an annual fertility program including nitrogen and sulfur, harvesting quality and pest management (diseases/insects). These differ somewhat from pure alfalfa stands and warrant understanding to maximize production.
Other U.S. regions have well-documented success with hay mixtures on a high percentage of the total forage acres. When correctly planted and managed, mixtures have multiple benefits by adding diversity to your operations in genetics and utility.
Reviewed in 2018