America With Cotton-Waste Mulch
By Don Comis
April 29, 2003
A new "hydromulch" spray
that includes cotton gin waste will be tested in June by
Agricultural Research Service scientists
and cooperators at Summit
Seed, Inc., of Manteno, Ill. Hydromulches are slurry mixtures that are
sprayed onto the ground for land reclamation, erosion control and other
Typically, hydromulches contain paper, wood or straw in a slurry mixture
with water and grass seed. The slurry, usually dyed green, helps the seeds
stick and stay in place and provides a moist and nutritious mulch for
The test hydromulches will have ryegrass seed in them and will be dyed red,
green or brown to distinguish between those made with wastes from different
cotton gin processes and regions. Agricultural engineers Greg Holt and Mike
Buser, with the ARS Cotton
Production and Processing Research Unit in Lubbock, Texas, and agricultural
engineer Daren Harmel and soil scientist Ken Potter, with the ARS
Grassland Soil and Water Research
Laboratory in Temple, Texas, will do the testing. Summit Seed will provide
equipment and supplies.
The researchers will compare the test hydromulches to three conventional
ones, looking at factors such as seed germination, costs and erosion control.
The waste is held together by a low-cost process--COBY, for Cotton
Byproducts--invented by the Lubbock scientists. It uses a hot, gelatinized
starch solution that acts as a glue and as a lubricant to smooth the mixture's
flow through extrusion equipment.
The scientists see this as another way to use waste material that cotton
gins would otherwise have to pay to have removed. These costs are estimated at
$4 million to $6 million annually.
The cotton-waste mixture has also been made into pellets and tested in
pellet-burning stoves and as fertilizer and cattle feed. In a test with 162
heifers, cattle gained more weight on less feed. And Summit Seed is testing a
dry mixture as a bedding mulch for landscaping use.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.