Organizers of the inaugural Tucson Compost Expo 2012 on Saturday hope to attract composting nerds and newbies, as well as non-gardeners.

"This is an exciting time in composting," says Erik Shapiro, special events coordinator of the Tucson Organic Gardeners, the group organizing the expo. "There's just a growing interest in it."

Compost is the product of organic material that's broken down by micro-organisms, says Shapiro, who teaches economics at Pima Community College.

It's used to amend soil for growing plants and is considered the organic alternative to chemical fertilizers.

Not all compost is the same, however, and Shapiro says the expo will demonstrate that.

For instance, likely exhibitor Arbico Organics creates a rich compost using sawdust and waste from its production of parasitic wasps that it sells to eliminate flies around horses.

Tanque Verde Farms, which also has expressed interest in participating, circulates heat in a way that quickly composts manure from Tanque Verde Ranch and kills off parasites and undesirable seeds.

"How cool would it be to have a selection of compost?" Shapiro says. "I anticipate people coming in with truckloads of compost."

Attendees could buy a variety of compost to mix into their residential pile or put directly into their gardens.

Other exhibitors will demonstrate the diversity of methods to create compost, which requires mixing sources of nitrogen and carbon with air, water and microorganisms.

Some methods include vermiculture, which uses worms, and compost tea, a blend that promotes microbial richness in soil.

These are more sophisticated measures compared with the simple, more familiar practice of mixing household food scraps, landscape litter and dirt.

Expo vendors will sell equipment for starting compost piles, says Shapiro, including bins and cranks.

Also expected to attend are the Compost Cats, a group of University of Arizona students, and the Community Food Bank of Southern Arizona. Both will share composting tips and discuss sources of free compost and composting materials.

Shapiro says one of the aims of the expo is to teach non-gardeners that composting is more than a gardening tactic. The practice keeps biodegradable material out of landfills and in useful food production.

"Even for people who don't garden, there is a huge reason for composting," he says.

If people don't want to compost themselves, they can give their food scraps and plant litter to those who do.

"We hope the expo helps generate ideas and connections, and furthers the amount of people who do care about (composting)," Shapiro says.

If You Go

Tucson Compost Expo 2012

• What: Exhibitions of compost, composting material, education and equipment.

• When: 10 a.m.-2 p.m. Saturday.

• Where: St. Mark's Presbyterian Church, 3809 E. Third St.

• Admission: Free.

• Information: 670-9158,

Contact local freelance writer Elena Acoba at