With recent drives to not only include native species,
but seed greater diversities of grasses, shrubs, and forbs in
post-wildfire restoration efforts, there's a need for seeding
equipment that is capable of simultaneously seeding seeds of various
size and shape and with many different types of appendages.
For example, small seeds often must be placed on the
soil, and pressed, but not buried, into the soil surface. These
small seeds are more successful when broadcasted. Larger seeds
should be covered with soil and therefore do best when placed in a
furrow created by a disk.
Modified Rangeland Drill
For many years, land managers have used rangeland
drills for post-wildfire revegetation efforts. Such drills have
been successful at effectively establishing a few species, often
introduced cultivars selected for reliable establishment, fast growth,
and palatability for livestock.
This drill is
durable and extremely rugged, however the traditional rangeland drill
must be modified to accommodate more complex seedings. Seed
tubes can be pulled from the disk assembly to allow seeds to fall on
the soil surface rather than into a furrow, but they are not pressed
into the soil, and may be buried by soil cast from the adjacent disks.
The addition of three seed boxes allows for broadcast species to be
Left: Drilled species are placed as the disks create
furrows, the chains place some soil over the seeds. Right: Every
other disk is lifted to allow areas for the broadcast species to
Furrows from the modified rangeland drill.
This newer minimum-till drill is a more complex piece of
equipment, but is designed to handle seeds with various shapes and
sizes, thus allowing a more diverse mix of species to be seeded.
The hydraulic system maintains consistent seeding
Interchangeable drilling disks and brillion
cultipackers allow for greater versatility for various seed mixes,
including simultaneous seedings of drilled and broadcast species.
Less surface disturbance may be beneficial in
conserving bilogical soil crusts and residual natives.
Left: The hydraulic tire/drill creates a
furrow for the drilled species which is set by a press wheel, then a
chain. Right: Brillion wheels press broadcast species into the
Furrows and brillion tracks left from the minimum-till