Establishing a good stand is critical for profitable forage production and requires attention to details for success. As discussed above, begin by selecting species adapted to soils where they will be grown. Plan well ahead of time so corrective lime applications have time to neutralize soil acidity, and soil fertility deficiencies can be corrected. Make sure fields are free of any herbicide carryover that can harm forage seedlings. It is also important to have controlled perennial weeds and winter annual weeds the year before seeding a forage stand. Refer to bulletin 789 Ohio, Indiana, Illinois, and Missouri Weed Control Guide and current labels for more information on herbicides with crop rotation restrictions.
An established stand having about six grass and/or legume plants per square foot is generally adequate for good yields. About 20 to 25 seedling plants per square foot in the seeding year usually results in good stands the following year. The following guidelines greatly improve the likelihood of successful establishment of productive forage stands.
Crop Rotation and Autotoxicity
Crop rotation is an important management tool for improving forage productivity, especially when seeding forage legumes. Crop rotation reduces disease and insect problems. Seeding alfalfa after alfalfa is especially risky because old stands of alfalfa release a toxin that reduces germination and growth of new alfalfa seedlings (called autotoxicity). This is especially true on heavy-textured soils. Disease pathogens accumulate and can cause stand establishment failures when seeding into a field that was not rotated out of alfalfa. Rotating to another crop for at least one year before re-establishing a new alfalfa stand is the best practice. If that is not possible, chemically kill the old alfalfa in the fall and seed the next spring, or spring kill and seed in late summer.
Seed Quality
High-quality seed of adapted species and varieties should be used. Seed lots should be free of weed seed and other crop seed and contain only minimal amounts of inert matter. Certified seed is the best assurance of securing high-quality seed of the variety of choice. Purchased seed accounts for only 20% or less of the total cost of stand establishment. Buying cheap seed and seed of older varieties is a false and short-lived economy. Always compare seed price on the basis of cost per pound of pure live seed, calculated as follows:
- Percent purity = 100% - (percent inert matter + percent other crop seed + percent weed seed)
- Percent pure live seed (PLS) = percent germination x percent purity
- Pounds of PLS = pounds of bulk seed x percent PLS
Seed Inoculation
Legume seed must be inoculated with the proper nitrogen-fixing bacteria prior to seeding to ensure good nodulation. Inoculation is especially important when seeding legumes in soils where they have not been grown for several years. Because not all legume species are colonized by the same strains of nitrogen-fixing bacteria, be sure to purchase the proper type of inoculum for the forage legume to be planted. Verify the inoculant expiration date and make sure it was stored in a cool, dry place. Because many seed suppliers distribute preinoculated seed, check the expiration date and reinoculate if necessary. If in doubt, reinoculate the seed before planting. The seed should be slightly damp and sticky before adding the inoculant. This can be accomplished with a syrup/water mixture or a commercial sticker solution. Soft drinks are also effective as sticking agents. Protect inoculants and inoculated seed from sun and heat as much as possible and plant soon after inoculation.
Seed Treatments
Fungicide-treated seed is highly recommended for alfalfa and may be useful for red clover. Metalaxyl and mefenoxam are systemic fungicides for controlling seedling dampingoff diseases caused by Pythium and Phytophthora during the first four weeks after seeding. These pathogens kill legume seedlings and cause establishment problems in wet soils. Many companies are marketing alfalfa seed treated with either of these fungicides. Various other seed treatments and coatings are sometimes added to forage seed. It is very important to calibrate seeders appropriately, especially when the seed has been coated. For example, lime coatings can account for up to one-third of the weight of the seed, so the actual number of seeds planted can be drastically affected on a weight basis. In addition, some seed coatings affect the flowability of seed, which can dramatically affect the seeding rate output of a planter. The manufacturers’ seeding calibrations for the planter are not likely to hold true for coated seed. A good video on how to calibrate a forage drill is available at forages.osu.edu/video.
Spring Seedings
Plant as soon as the seedbed can be prepared after March 15 in southern Ohio and April 1 in northern Ohio (Table 7.8). Spring seeding should be completed by early May in northern Ohio and by late April in southern Ohio. With early seeding, the plants become well established before the warm and dry summer months. Weed pressure increases with delayed seeding. Annual grassy weeds can be especially troublesome with delayed spring seedings. Herbicides are usually essential when seeding late in the spring. Refer to bulletin 789 Ohio, Indiana, Illinois, and Missouri Weed Control Guide for guidelines on weed management and for specific herbicide options.
Late-summer Seedings
Late summer is an excellent time to establish many forage species, provided sufficient soil moisture is available. August is the preferred time for late summer seeding because it allows enough time for plant establishment before winter. Do not use companion crops with August seedings because they compete for soil moisture and can slow forage seedling growth to the point where the stand will not become established well enough to survive the winter. Refer to bulletin 789 Ohio, Indiana, Illinois, and Missouri Weed Control Guide regarding late summer forage seedings.
Sclerotinia crown and stem rot are serious disease threats when seeding alfalfa and clovers in late summer. The risk of infection is greatest in fields where forage legumes have been grown recently and when minimum tillage is used. Sclerotinia infects seedlings in the fall, but injury is not visible until plants begin to die in late winter and early spring. Crop rotation, conventional tillage plantings, and seeding by early August reduce the risk of severe damage from this disease. A limited number of alfalfa varieties have some resistance to this disease.
Conventional Tillage Seeding
The Ideal Seedbed for conventional seedings is smooth, firm, and weed-free. Don’t overwork the soil. Too much tillage depletes moisture and increases the risk of surface crusting. Firm the seedbed before seeding to ensure good seed-to-soil contact and reduce the rate of drying in the seed zone. Cultipackers and cultimulchers are excellent implements for firming the soil. The lack of a firm seedbed is a major cause of establishment failures. The soil should be firm enough at planting so that a footprint is no deeper than 1/2 to 3/4 inch.
Seeding Depth for most cool-season forages is 1/4 to 1/2 inch on clay and loam soils. On sandy soils, seed can be placed 1/2 to 3/4 inch deep. Seeding too deep is one of the most common reasons for seeding failures. Some seed should be visible on the soil surface when seeding at the right depth for most forages. If no seed is visible on the soil surface, then it is likely that the seed is being planted too deep. This is especially true for no-till forage seedings.
Seeding Equiptment, such as many different types of drills and seeders, can help establish forage stands can be established with many different types of drills and seeders, provided they are adjusted to plant seed at an accurate depth and in firm contact with the soil. When seeding into a tilled seedbed, drills with press wheels are an excellent choice. If the seeder is not equipped with press wheels, cultipack before and after seeding in the same direction as the seeder was driven. This ensures that seed is covered and in firm contact with the soil. Cultipacker seeders, such as the Brillion seeder, provide accurate and consistent seed placement in tilled seedbeds.
Fluid Seeding is a technique being used to seed forage legumes. Seed is distributed in a carrier of water or in a fertilizer solution. Custom application is recommended because it requires special equipment for good seed suspension and distribution. Prepare a firm seedbed and cultipack after the seed is sprayed on. For fluid seeding, seed should be mixed into solution at the field and applied immediately. Some producers are also having success with seeding legumes through dry fertilizer air spreaders, with cultipacking before and after the seed is broadcast.
No-Till and Minimum-Till Seeding
Many producers are successfully adopting minimum and no-till practices for establishing forage crops. Advantages include soil conservation, reduced moisture losses (important for late summer seeding), lower fuel and labor requirements, and seeding on a firm seedbed. Most forage species can be seeded no-till with proper management. Such species as red clover that have good seedling vigor are the easiest to establish. Notill forage seedings are most successful on silt loam soils with good drainage. Consistent results are more difficult on clay soils or poorly drained soils. Weed control and sod suppression an essential for successful no-till establishment, because most forage crops are not competitive in the seedling stage.
Seed Placement is critical with reduced tillage. It is very easy to plant seeds too deep with no-till drills. A relatively level seedbed improves seed placement. A light disking may be necessary before attempting to seed. Plant seed shallow (1/4 to 1/2 inch, in most cases) in firm contact with the soil. If some seed is not visible on the soil surface after passing over it with the no-till drill, then it is likely the seed is being planted too deep. Crop residue must be managed to obtain good seed-to-soil contact. Chisel-plowing or disking usually chops residue finely enough for conventional drills to be effective. When residue levels are greater than 35%, no-till drills are recommended.
For No-Till Planting Following Corn, plant as soon as the soil surface is dry enough for good soil flow around the drill openers and good closure of the furrow. Perennial weeds should be controlled in the previous corn crop. If perennial weeds are still present, apply glyphosate before seeding. If any grassy weeds or winter annual broadleaf weeds are present in the field, use paraquat or glyphosate before seeding. Most drills can handle corn grain residue, but removal of some of the residue (e.g., for bedding) often increases the uniformity of stand establishment. Most drills do not perform as well when corn stalks are chopped and left on the soil surface. Be sure to avoid problems with carryover of triazine residue from the previous corn crop.
Following Small Grains, no-till seeding of forages in late summer conserves valuable moisture. Weeds should effectively be controlled in the small grain crop. Ideally, wait to plant the forage crop until at least 1/2 inch of rain has fallen postharvest to stimulate germination of volunteer small-grain seeds and weeds; however, do not delay planting beyond the recommended seeding date for your area. Burn down any weeds and volunteer small grain seedlings before seeding the forage crop. Glyphosate can be used if thistles, Johnsongrass, or other perennial or biennial weeds are present in the small grain stubble. Remove straw after small grain harvest. It is not necessary to clip and remove stubble; however, it may be removed if additional straw is desired. Do not clip stubble and leave it in the field, as it may interfere with good seed-to-soil contact when seeding forages. If volunteer small grains become a problem after seeding, apply a selective grass herbicide to pure legume seedings to remove excessive competition prior to late autumn.
Insect Control can be a serious problem in notill seedings, especially those seeded into old sods. Slugs can be especially troublesome where excessive residue is present from heavy rates of manure applied in previous years. Chemical control measures for slugs are limited to baits containing methaldehyde (Deadline products) and iron phosphate (e.g., Sluggo). Lorsban insecticide products are registered for use during alfalfa establishment for suppression of various soil insects.