Several of these machines have been modified to mount on the front of a small tractors or all-terrain vehicles. The spinning brush creates a vacuum that pulls the seed head into the brush, which removes the seed and deposits it into the hopper. When collecting seed with the intention of restoring prairie sites it is important to remember that no one collection technique or period of time will provide all the seed species that are desired. The decision on whether to purchase seed or collect it for the restoration site is dependent on the goals and objectives. Also, which method to select is not an either or situation.
Collection often involves a mixture of techniques which are selected by the restorationist.
Personal Communication Faessler, F. and Apfelbaum, S. 1988. Large scale harvesting of prairie seed. Knapp, E. and Rice, K. 1994. Starting from seed. Mahler, D. 1988.