Drills and Seeders

Selection of equipment for the seeding operation should be based upon three main objectives: (1) preparation of the best possible seedbed (2) weed control and (3) seed:soil contact. No single piece of equipment is best for all seeding situations. The type of grass seeding equipment available will strongly influence the options for seedbed preparation. If seeding into standing stubble or crop residue a double disk, furrow drill, or no-till drill with coulters will be required to achieve proper seed placement.

The technician and operator must consider all the factors for each individual situation, and then pick the best machine available. Frequently, there is no satisfactory machine available. In this case, the operator should be told frankly the chances of success are poor and they should either wait until conditions prevail that are favorable to success with the machinery available, or until they can obtain adapted equipment.

A. Disk Drills

Single-Disk

Single-disk drills are particularly adapted for seeding hard and brushy seedbeds. They can be obtained in standard, semi-deep, and deep-furrow models.

Double-Disk

Double-disk drills are useful for seeding in stubble and on well-prepared seedbeds. They work best when equipped with depth bands; spring pressure can then be applied to assure uniform penetration in soft and hard ground. Depth bands can be made locally from scrap iron, or commercial types can be purchased. For best results, the disks should be kept sharp.

This is a good grass drill showing double-disk openers with depth bands and packer wheels.

B. Deep-Furrow

The deep-furrow drill puts seed in the moist soil in the bottom of a deep furrow, yet the seed are only covered the normal depth in the bottom of the broad furrow. Deep-furrow planting may be done with either a lister (also called shovel) or a disk-type drill. Deep furrows are particularly useful where surface soil drying is a problem and for seeding through trash or stubble cover and into deep, loose seedbeds.

Snow and rainfall tend to concentrate in the furrows and drilling should be on the contour on sloping land. In stubble seedings the furrow drill parts the stubble, allowing more sunshine to reach the ground which may speed up germination.

Deep-furrow planting is not without its dangers and should be confined to relatively stable soils. In loose or erodible soil, the soil may slough in, covering the seed too deeply. High intensity summer storms or high winds can fill the furrows with eroded material and bury seed or seedlings.

C. Semi-Deep Furrow (Hoe Drill)

The semi-deep furrow disk drill forms a smaller furrow and has many advantages of the deep-furrow disk drill. The disks have less concavity and the planting shoe is smaller. To benefit from this type of drill, the furrow should be at least two inches deep.

D. Other Drills

Air seeders are excellent planters for cereal grains, but seeding depth must be monitored for perennial grasses and forbs. Also, fluffy seeds tend to plug drop tubes. A carrier is recommended to facilitate an even flow.

Numerous other interseeding or special drills for seeding grass are also available. No-till drills can be used to plant into heavy cereal stubble. Other drills have cotton seed boxes with special force-feeding devices for seeding chaffy seeds. They also have fine-seed hoppers.

Grass and legume seed boxes are available for most grain drills and are very useful for seeding fine seeds. Most grass seeds are best distributed through the standard grain box, however, agitation is required. When legumes are seeded with grasses, it is generally best to use both boxes, so that separation of small and large seeds in the drill box can be avoided. Also, the percent of legume in the established stand can be better controlled by seeding the legume only in every second or third row.

Alternate row seeding is easily accomplished when grass is seeded through the grain box and legumes through the fine-seed hopper by blocking alternate rows in each box with duct tape or small bags of sand (about one pound).

E. Broadcast and Other Seeders

Broadcasting is generally not a good method of seeding large-seeded species. Specialized seeders such as the Brillion is an excellent seeder for small-seeded turf species such as Kentucky bluegrass. Broadcasting onto a roughened surface combined with excellent packing and immediate precipitation has also been successful. In most cases, the recommended seeding rate should be doubled to compensate for seed buried too deep or that dry out on the surface. Broadcasting is most successful when used as a dormant fall or winter seeding on deep, loose seedbeds or on fresh burn areas where wetting/drying or freeze/thaw will cover the seed and increase the chance of germination.

Fertilizer spreaders are commonly used for grass/legume seedings. The Valmar™ is an orifice gravity flow with a paddle spinning wheel. An air-flow propels seed at a high velocity down vertical tubes onto the soil surface. The force can impregnate the seed into previously packed and then re-roughened soil surface. Both mechanical broadcast seeders require packing after seed application.

This is a packer following a broadcast seeder.

For small areas, hand broadcasting is the most practical method. The small hand (knapsack) broadcasters will give a more uniform seeding than scattering by hand. For large areas some type of power broadcaster is desirable. Power broadcasters are normally run by gasoline engines, electric motors, or the power take-off on the tractor. The hopper must be equipped with a good agitator or seed will not flow through it smoothly.

Two-wheel fertilizer spreaders can be used for very fluffy seeds that will not pass through conventional drills. Seed should then be covered with a packer.

Drills and broadcasters should be operated at rather low speeds (under two miles per hour) for the best performance and uniform seed delivery. When operated at higher speeds, there will likely be many "skips", disk penetration will be much more erratic, and furrow openers will throw soil into adjoining furrows.

The airplane and helicopter are excellent for broadcasting large areas. The Venturi type of seed distributor is advised for use on airplanes. Field flagging will be necessary to prevent overlap and skips. Where landing fields are distant and elevations not too high, the helicopter may be better than the airplane. It can land in any small clearing, and requires less ground control. It should be equipped with standard dusting hoppers..

This is an aerial broadcast seeding following a fire.

Machinery alone cannot guarantee success in getting good stands of grasses and legumes. But it is one of the factors we can control, to increase our chances of seeding success.

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Last Modified: 07/05/2007