The raunchy reputation of backyard composting is both undeserved and unnecessary, according to waste-management educators at Cornell University who reveal a few tricks of the trade in a new instructional video, Compost Truth or Consequences.

"We're not talking rocket science, but if your compost goes anaerobic and starts to smell, the neighbors may think you're a mad scientist," says Veet Deha, a composting educator at Cornell Cooperative Extension of Tompkins County. "All you need for neighbor-friendly composting is the knowledge of a couple basic principles."

Since home composting of food scraps and yard debris can reduce waste by 20 percent and provide a valuable soil amendment, helping people do it right makes sense, the educators at the Cornell Waste Management Institute reasoned when they made the instructional video. Loosely based on the old television quiz show "Truth or Consequences," the video finds backyard composters suffering the consequences of composting-gone-wrong. Along comes a helpful Master Composter with the truth:

-- A rotten-egg smell is caused by so-called anaerobic decomposition, when oxygen fails to reach overly moist waste materials and anaerobic microorganisms, which thrive in the absence of oxygen, take over.

-- An ammonia smell is caused by too much green nitrogen-rich material, such as grass clippings, in the compost.

Anaerobic compost can be rescued, the Master Composter says, by adding dry "bulking" materials, such as straw or wood chips, so that oxygen penetrates the compost and encourages aerobic microorganisms to re-establish themselves. The solution to an excess of, nitrogen is to add brown, carbon-rich materials, such as dry leaves.

The instructional video provides easily understood details on the conditions needed for composting: Proper moisture, air, a favorable mix of carbon materials and nitrogen, as well as plenty of surface area for the "decomposer" organisms to nibble.

"Home composting benefits the entire community because it keeps tons of organic material out of the waste stream and reduces the cost of waste-handling for everyone," says Ellen Z. Harrision, director of the Cornell institute. "And each household benefits, too, by keeping organic materials at home and turning them into nutrient-rich soil amendments for gardens, lawns, flower beds and plant containers." She says the instructional video should be of interest to a wide audience, from community educators and garden clubs to individuals who want to get the most out of their composting efforts.

The 15-minute, $25 video and a two-part $12 manual to help people get a Master Composter program started are available separately (or together for a total of $30) from the Cornell University Resource Center, 7 Business and Technology Park, Ithaca, N.Y. 14850; phone (607) 255-2080; fax (607) 255-9946; e-mail Dist_Center@cce.cornell.edu or by visiting the web sitehttp://www.cce.cornell.edu/publications/catalog.html