DATE:     11/14/96  
CONTACT:  Dr. Ahmad Khalilian, (803) 284-3343
          Dr. Fran Wolak, (864) 656-4075
WRITER:   Tom Lollis, (803) 284-3343

Will Trash Move from Kitchen
Table to the Cotton Field?

     BLACKVILLE -- Today you will send that empty cereal box on a
one-way trip to the county landfill. One day your empty cereal
boxes and other household trash could help enrich soil for crops
on the farm.
     "In the average South Carolina home each person generates
5.6 pounds of solid waste every day, according to the Department
of Health and Environmental Control," said Fran Wolak, Clemson
Extension coordinator for municipal solid waste education.
     That comes to about 3.8 million tons of solid waste over a
year's time, and he estimates that as much as 80 percent of that
total could be turned into useful organic matter through
composting. The technology exists.
     "A company called Bedminster Bioconversion Corp. has built
plants in several states. The latest opened in Cobb County near
Atlanta this spring. It takes in 300 tons of municipal waste and
100 tons of sewer sludge every day and converts it all, in a
three-day process, into 100 tons of compost," Wolak said.
     "We don't have enough backyard gardeners to buy all that, so
agriculture will have to be the end user," he said. But what
happens when you put all that compost on farm land?
     Clemson University research and Clemson Extension faculty
are trying to figure that out under a $100,000 grant from the
South Carolina Universities Research and Education Foundation,
about $7,000 from the S.C. Cotton Board and the assistance of 60
tons of compost donated from Bedminster's Sevierville, Tenn.
plant over the last two years.
     "We've used it as a soil amendment for cotton, putting out
three different rates -- 5, 10 and 15 tons per acre," said Ahmad
Khalilian, research agricultural engineer at Clemson's Edisto
Research and Education Center at Blackville. Results in 1995
indicated potential for increased crop yields, more profits and
improved soil quality.
     "Our numbers showed an extra 63 pounds of lint cotton where
we applied 15 tons per acre in an eight-inch band over the row or
broadcast over the entire field. At 80 cents a pound, that would
be about $50 more an acre," Khalilian said. The compost also
increased the amount of organic matter in the top eight inches of
the sandy Coastal Plain soils -- from .85 percent to 1.2 percent
at 5 tons and up to 1.5 percent at 15 tons.
     Soil nitrogen content also increased. Where no compost was
added, the soil contained 9.38 parts per million (ppm) of
nitrogen. When the high rate of compost was added the numbers
went to 16.4 ppm. The organic matter and nutrient analyses have
been done by Bob Lippert, Clemson Extension agronomist for plant 
nutrition.
     "The compost contains 1.2 percent nitrogen, so it adds slow-release nitrogen to the soil, making the fertilizer the farmer
puts out more efficient," Khalilian said. Using compost may allow
farmers to cut back on nitrogen fertilizer.
     "We have to test that, though," he said. He has no
reservations, however, about compost improving soil conditions in
the sandy Coastal Plain.
     One of the big problems in sandy soils is that equipment
repeatedly running across a field will create a hardpan layer
from 10 to 14 inches below the surface. It must be broken with
deep tillage equipment to allow plant roots to get to the
nutrients found in the clay layer.
     Adding compost to the soil raises the level of organic
matter, which increases water holding capacity and makes the soil
more resistant to compaction.
     "If we could eliminate the compaction problem, farmers could
save at least $10 per acre on deep tillage operations," Khalilian
said. "We are working on a plan to inject the compost under the
row, which may do exactly that."
     Researchers are asking several other questions about the
compost.
     "If we band it, what does it do to weeds and seedling
disease?" Khalilian said. Those questions have not yet been 
answered.
     How about insects? Mike Sullivan, research entomologist at
the Edisto REC, has seen no effect from the compost.
     "The insects still love to feed on the cotton plants," he
said.
     Will it help control nematodes, those microscopic worms that
feed on plant roots?
     John Mueller, plant pathologist at Edisto REC, said that
it's possible that compost will increase the activity of fungi
and bacteria which are antagonistic to nematodes.
     "We may be able to prevent the buildup to economic levels.
It's already been shown that poultry litter can decrease nematode
populations through that indirect effect," he said.
     Wolak and fellow agricultural engineer Dick White regularly
analyze samples of the compost for nitrogen content, heavy
metals, carbon-nitrogen ratio and foreign matter.
     "If the farmer begins using something like this in the
future, he'll want a label telling him what's in it and how he
can use it," Wolak said. "So far it seems to be high in quality
and should cause no problem if used on agricultural land."
                               END