By Laura Martin

MISSISSIPPI STATE -- Mississippi's vast amounts of wood waste and poultry manure are serious disposal problems in a state where these two industries generate the most agricultural income.

In 1999, Mississippi's poultry industry reached a record $1.55 billion in estimated farm gate value. Each year it produces an estimated 600,000 tons of litter.

The state's forestry industry yielded an estimated $1.33 billion in farm gate value in 1999. The forest products industry in Mississippi produces a large quantity of wood waste during their manufacturing cycles. The amount of wood waste that is not used has become a heavy economic burden of the forest products industry due to increased landfill costs, transportation costs, environmental concerns and governmental regulations. Alternative waste disposal options would greatly benefit both industries.

A group of researchers at Mississippi State University's Forest and Wildlife Research Center is evaluating composting wood waste and poultry manure as one solution to these large problems.

"Two problems in the state are wood wastes and poultry wastes," said Dr. Hamid Borazjani, a professor with MSU's Forest Products Laboratory. "Composting gets rid of them in an environmentally friendly way. It is the most economical way of dealing with these two problems."

Composting is the biological decomposition and stabilization of organic materials. These conditions produce a final product that is stable, free of pathogens and plant seeds, and can be applied to soil to improve its characteristics.

In the study, researchers composted primarily wood waste from a furniture manufacturer, small amounts of fabric scraps and other compounds that are difficult to separate from furniture scraps. They mixed local poultry manure with the wood waste.

Results of their study indicated that composting could be an economical, simple, safe and viable option for disposal of wood wastes. Because of the small particle size, these types of compost are well suited as a soil additive in areas with low organic matter.

Several area wood manufacturers could combine their resources and build a large-scale, composting site and supply local farmers and nurseries with the product. Research is continuing with other types of manure and agricultural residues.

"It is a relatively simple operation. Plant owners who want to have a composting site on their property need a grinder, mixer, and a tractor or windrow to turn the mix over," said Sandy Stewart, a research scientist with the Forest Products Laboratory. "Lumber mills, construction companies, furniture companies and dry wall businesses may find composting is an effective alternative for disposal.

"Composting can get rid of the cellulose and toxins in wood that are detrimental to plant growth and produce a stable product that can be a soil conditioner or mulch."

The pilot scale study included grinding the hardwood waste, mixing in the chicken litter and allowing it to stand for three months, aerating weekly. The scientists studied 18 piles with different levels of manure mixed in: 10 percent, 20 percent or 30 percent by weight, including three control piles with no added manure.

Borazjani and Dr. Susan Diehl, an associate professor with MSU's FWRC, measured weight loss, nutrient levels and toxicity levels. The piles with no manure took longer to break down than the ones with added manure in them. All treatments resulted in reduced weight within 60 days.

The percentage of manure mixed with wood can be changed depending on the availability of poultry litter in the area.

"Composting uses different kinds of waste to make a useful product," Diehl said. "They decay faster together because there are nutrients in chicken manure that aren't in the wood. Nutrients in the manure accelerate the rate of degradation and growth of microorganisms."

Samples from the pilot scale study are being tested in nurseries as a potting media for ornamental plants. Nurseries or farmers may choose to mix the compost with other soil as an additive to be used for ornamental plants. Based on the nursery results, hardwood compost could turn out to be a very good potting soil, Borazjani said.

The compost also has been studied on row crops including corn and cotton. Results show the compost is as good an amendment as fertilizer and potting soil.

"Composting at an industrial level seems to be catching on. Individuals have been composting for a long time," Borazjani said. "They make compost out of leaves and kitchen waste. This is basically the same thing but we are using wood and manure.

"This produces a quality material to be used in agriculture and nurseries. It is a fantastic product."

Contact: Dr. Hamid Borazjani, (662) 325-3106