DEFINITION
Compost refers to the process of consciously collecting and aggregating organic materials - often food scraps and yard or lawn clippings - into a container or pile where it is broken down by bacteria, fungi, and other microfauna into a nutrient-rich soil-like material that can be used for growing plants and amending/improving soil.

Composting can occur on many scales, from a worm bin inside an apartment, to backyard (or front yard, median) compost bins, to municipal collection and large-scale industrial compost systems. Composting can also be utilized on the farm. Thus there are many opportunities to integrate compost into Green Infrastructure, and thus recycle energy and nutrients embodied in organic 'waste' back into the landscape quickly, efficiently, and in a healthy manner.

Raw materials include: bark, paper mill sludge, cardboard, peat moss, cattle manure, poultry manure, crop residue ,sawdust & shavings, seaweed & other aquatic plants, fish processing wastes, septage & sewer sludge, food processing wastes, slaughterhouse & animal wastes, fruit & vegetable wastes, meatpacking waste, grass clippings, spoiled hay & silage, horse manure, straw, leaves, swine manure, lime, wood ash, livestock manure, wood chips, newspaper, etc... Due to its high nitrogen content, poultry manure makes the best compost.

AKA
compost tea, vermicompost, worm bin

PERFORMANCE CRITERIA
The correct approach to composting requires more than simply tossing wastes in a bin. If done incorrectly, potential problems include odors, flies and other vector problems, weeds and pathogens. Proper aeration will control the rate of moisture removal and regulate the temperature of the mix, thus maintaining the proper rate of aerobic digestion. Strong odors are usually due to anaerobic activity and indicate that there is too much moisture in the mix.

Breakdown of raw materials will depend on the carbon to nitrogen (C:N) ratio, available oxygen supply (aeration), moisture content, temperature, and pH of the compost pile. Properly managed composting increases the rate of natural decomposition and generates sufficient heat to destroy weed seeds, pathogens, and fly larvae. By virtue of the fact that it adds organic matter (humus) back to the soil, compost is considered an important conditioner.

ILLUSTRATION

source: http://www.daviddarling.info/encyclopedia/C/AE_composting.html source: http://www.richmond.ca/__shared/printpages/page1990.htm



CASE STUDIES