The Composting Process

• Decomposition naturally occurs when organisms like bacteria, insects, fungi and worms feed on plant and animal matter. The end product is compost. The speed of decomposition depends on the temperature, moisture level, mix of materials, and exposure to air, which aid composting organisms.
  
  

Compostable Materials

• Green materials, such as grass clippings, fresh plants and food waste; and brown materials, such as dead leaves, twigs, straw, wood chips and branches, make up a compost pile. The quantities of browns and greens should weigh about the same. The right mix of nitrogen-rich greens, carbon-emitting browns and moisture increases decomposition. Other compostable materials, which may attract pests, include: meat waste, bread, eggshells, cheese, pasta, food-soiled paper waste and herbivore manure. Unfit items include plastics, rocks, black walnut trees and carnivore feces.
  
  

Passive Composting

• At home, you can pile compostable materials, bury green materials under about 8 inches of compost and keep all materials moist. Layering or mixing materials works equally well. Over time, the pile will compact and decompose. Depending on conditions, it takes one to two years to produce compost. This is the slowest way to produce compost and suitable for eliminating kitchen waste.
  
  

Managed Composting

• There are ways to speed decomposition. Shredding items and properly mixing green and brown materials increases decomposition. Keeping the pile moist, similar to a wrung out sponge, aids decay. Using less-compactable items or turning the pile helps ventilation. A productive compost heap will heat up to somewhere between 104 and 131 degrees. A well-managed pile will produce compost in three to four weeks.
  
  

Equipment

• Bins and tumblers are often used to hold compostable materials. Bins made of wood, wire or plastic aid in resorting materials. Similarly, tumblers jumble contents when flipped. Both containers have aeration holes, keep out pests, minimize odors and help maintain moisture and heat levels.
  
  

Troubleshooting

• Problems with moisture levels, ventilation, material mixture and temperature can slow decay, attract pests and smell bad. Too much moisture causes odors and too little decreases productivity. Adding water, covering or shading the pile, mixing the pile, or changing ventilation may be necessary. Too many green materials make an ammonia smell and too many brown materials slow decomposition. Keeping materials insulated in cold weather also maintains decay. Minimum pile size, ideally 9 square feet, can preserve temperature and moisture. Pest problems often result from adding improper compost materials or poorly burying kitchen scraps, but insects, slugs and millipedes are healthy and normal.
  
  

Benefits

• Composting keeps household and garden waste out of the landfill and creates nutrient rich soil for gardening. According to the EPA, organic waste buried in a landfill decays anaerobically and creates methane, a greenhouse gas 21 times more potent than carbon dioxide. A properly ventilated compost pile, which only decays aerobically, only produces carbon dioxide.