What Is Drill Seeding?

Purpose

• Seeding ground with grass or grain helps prevent the soil in the area from eroding, thus playing a critical role in maintaining the local ecosystem and the fertility of its farmland. Drill seeding is one of several techniques used to seed a piece of landscape or farmland soil, including hydroseeding and airborne methods. Drill seeding's direct approach, however, offers a distinct advantage over these other methods. According to Grass Plus Incorporated, drill seeding does a better job of ensuring even coverage and successful plant growth than hydroseeding. It also requires only half the amount of seed to achieve comparable results.

Process

• In drill seeding, workers pass a seed driller over disturbed or, ideally, cleanly tilled soil, dropping seed directly into the soil. This process calls for relatively flat ground with a horizontal-to-vertical ratio of at least three to one for best results. The various types of seed get filtered into a metering mechanism to ensure even distribution, with incompatible seed types filtered into separate seedboxes, according to Texas A&M University's Revegetation Equipment Catalog. The seed driller distributes the seed into furrows as it rolls across the soil.

Equipment

• Seed drills vary in size and capability depending on the duties they must perform. Grain drills may extend up to 40 feet in width, while grass drills generally take up only a fraction of that space. A trailer or hydraulic lift pulls the drill across the soil. In cases involving well-tilled soil with minimal rocks or other debris, seed drills with double-disc openers and presswheels can push the seed into the soil with ease. More challenging terrain may call for other attachments such as coulters or chain drags to destroy and eliminate obstacles. The U.S. Forest Service uses rangeland drills to seed many areas in the western part of the country.

Considerations

• Choosing the right kind of seed drill or seed drill attachment for the job calls for an understanding of each seeder's capabilities and limitations in specific environments. A seeding system with ordinary drill openers designed for large-scale coverage of level, tilled farmland will stand little chance against rocky or bumpy land. The type of terrain also dictates what kind of row spacing the drill should use, ranging from an 8-inch row width for pre-tilled soil to a 12-inch row width for more challenging ground.