Garbage in, Compost Out
What do you get when you mix municipal yard waste, manure from the Illinois State University Farm and food scraps from several Bloomington-Normal food service facilities?
A recipe for diverting more than one million pounds of waste from the McLean County landfill every year and converting it to a usable product: compost.
“The program started as a research project on how urban areas and agriculture can work together to solve problems,” says Russell Derango, ISU Farm Manager.
The town of Normal wanted a better solution for disposing leaves, grass clippings and yard waste. High phosphorus levels in the livestock manure at the ISU Farm limited its use as fertilizer. In 1993, the two entities established a partnership to address both problems.
“We expanded and started whole food waste composting about four years ago,” Derango says.
Food scraps from ISU dining halls as well as corporate food facilities and a couple of local grocery stores are hauled up to the 16 acre compost site at the farm.
Composting is essentially managed decomposition of organic materials. Mixing carbon and nitrogen containing wastes in the right ratio creates favorable conditions for microbes to breakdown the materials into a soil like substance.
“The process produces heat,” says Dr. Ken Smiciklas, ISU Agronomy Professor. “The compost needs to reach 140 F to kill harmful bacteria and weed seeds.”
A compost aerator mixes the materials and incorporates the air needed for microbial aerobic digestion to decompose the materials
The windrows of waste are periodically turned with a compost aerator for even decomposition and incorporating air.
After about six months, the compost is ready to be used to add organic matter and nutrients to soil. The compost is used on the ISU farm, for landscaping and sold to the public.
“The biggest issue we have is the amount of trash mixed in with the yard waste,” Derango says. “We really need people to follow the rules and separate their trash.”
Anything that is not biodegradable like plastics, metals and rocks has to be screened out and it can also be dangerous for the farm workers.
“We’ve had large rocks get kicked out by the aerator and thrown through the back windshield of the tractor,” Derango says.
If you would like to purchase compost, for the cost is $25 per pick-up truck load and it can be picked up at the farm during regular business hours. Click here to contact the ISU University Farm.