Ground speed : its influence on the direct seeding of jack pine (Pinus banksiana Lamb.) with the Bracke scarifier
Abstract
The effects that ground speed and obstacle height have
upon microsite creation by the Bracke scarifier and upon the
seeding characteristics of the integral seeder were studied.
The study was conducted in a former gravel pit with
homologous soil conditions and uniform obstacle sizes to
minimize sources of variation. Jack pine {Pinus banksiana
Lamb.) seed was treated with ^Scandium, a gamma-emitting
labelling agent. The trial involved running the
scarification unit at four speeds, over three obstacle sizes.
Data were collected on microsite dimensions, seeder
performance and seed placement. A field trial was also
conducted to follow trends seen in the gravel pit portion.
Results indicated that the height of an obstacle had more
effect on microsite attributes, seeder performance and seed
placement than did the ground speed at which the scarifier
was drawn. Microsite length and longitudinal seed placement
decreased as obstacle height increased, while lateral seed
placement increased with increasing obstacle height. It was
recommended that the Bracke scarifier/seeder be operated at
40 m/min in order to reduce the influence of obstacles. The
seeder must be properly calibrated to account for the
influence of obstacles: a modified technique was discussed.
Trends observed in the gravel pit trial were not apparent in
the smaller field trial.
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- Retrospective theses [1604]