Development of Agitators for Seeding Forages Using Air Delivery Systems

Abstract

Air seeders or air drills traditionally have been used for minimum till and direct seeding of cereal, oilseed, and pulse crops. These seeders use an air delivery system to move the seed from a large grain tank to cultivator furrow openers or boots. Air seeders have all the weight of the cultivator attachment on wheels, whereas the air drill cultivator attachment has the weight distributed to caster wheels on the front and the packer wheels on the back. These units have not been used extensively for forage seeding because of seed bridging problems with some types of grass seed over the metering system entry points in the seed tank. This study designed and evaluated modifications to the agitation and metering systems for seeding forages using 3 different types of Canadian-built air seeders. Meadow brome grass (Bromus riparius Rehmann) was used in the seeding trials because of its extreme susceptibility to bridging. The agitator systems for 3 different types of commercially available air seeders were modified with the ultimate goal to design a configuration that reduced seed bridging and provided uniform seed output. Tests were also conducted with a seed and fertilizer mixture as another method of improving uniformity of seed metering and output. None of the air seeders were able to meter and distribute pure meadow brome seed without the use of a modified agitation system. The Bourgault 3165 air seeder was able to effectively meter and distribute the meadow brome grass seed and fertilizer mixture without the agitator modifications and was able to meter and distribute pure meadow brome grass seed with the addition of the modified agitator. The Flexi-coil 172 air seeders required the addition of a horizontal agitator to effectively meter and distribute the seed and fertilizer mixture, and the Morris 6130 was unable to output the mixture of meadow brome grass seed and fertilizer uniformly despite agitator modifications. Field-scale testing indicated that grass forages could be successfully seeded using a full- size air seeder with these modifications.