Compost is the aerobically decomposed remnants (waste) of organic matter.
Given enough time, all biodegradable material will compost, and the primary objective in the modern push to compost is to capture readily degradable materials so they do not enter landfills. However, most small-scale domestic systems will not reach sufficiently high temperatures to kill pathogens and weed seeds or deter vermin, so pet droppings, scraps of meat, and dairy products are often best left to operators of high-rate, thermophilic composting systems. Hobby animal manure (horses, goats), vegetable kitchen and garden waste are nevertheless all excellent raw material for home composting. Early roots of composting as a treatment for municipal solid waste were spurred by awareness of the trash crisis as early as the 1950s, and the rise worldwide of large MSW composting plants in the 1960s into the 1970s was virtually unregulated. Public outcry in Europe against contamination of soils on farms and vineyards from MSW compost containing residues of plastic, metals and glass triggered a shakeup of the industry, and in the 1980s a phasing out of MSW composting.
One ton of compost can save 219 gallons of propane, 140 gallons of oil