Why is Composting Important?

In natural systems, no such thing as "waste" exists. Energy and matter captured by life processes are released upon the breakdown of organic substances only to be re-utilized by living organisms within the system. Long-term soil fertility is maintained in natural systems because the residues of biological decomposition are reused by them to foster new growth. The transformation and flow of the nutrient-containing chemical compounds involved in this process is often referred to as "nutrient cycling". Nutrient cycling helps ensure the stability of natural systems over time by linking the processes of synthesis (build-up) and degradation (breakdown).

This intricate cycle can be disrupted when components from within the system are removed without being replaced. The large-scale extraction of natural resources for humanity’s benefit seriously alters natural ecosystems. Where this has happened, it has presented societies with two major challenges. One challenge is to avoid resource depletion. The other is the accumulation of huge quantities of unused resources we call "waste".

In terms of the soil ecosystem, intensive cultivation practices used to produce mass quantities of food and fiber have (in many cases) left soils depleted of organic matter and vital nutrients, thus making them less naturally productive and more vulnerable to erosion. After humans consume the commodities, by-products of their decomposition often are not returned to the soil. Instead, they become part of the voluminous wastestreams which modern societies are having difficulty handling.

The composting of organic materials can help remedy this situation by capturing the energy and matter released in the decomposition process. Composting transforms organic "waste" products into a nutrient-rich soil amendment capable of improving depleted or disturbed soil environments. By the intentional act of composting, humans participate in what has been called nature’s "Law of Return" because a vital link is established for the return of organic matter to soil systems. By including composting in human-devised waste management systems, they become more reflective of natural patterns, and more sustainable in the long run. The organic matter resource is conserved, and problematic wastes are converted into a beneficial product that can be sold to help finance the composting operations.

When managed effectively, composting ensures that the finished product can be safely returned to the appropriate environment. The composting process helps to disinfect organic wastes (by killing pathogens), to sterilize weed seeds (which may be present in organic residues), to decompose (many) toxic substances and to stabilize nutrients in the compost (which have the potential to be lost or to negatively impact the environment). Processing organic materials prior to composting them aids in the reduction of physical contaminants such as plastic, glass or metal objects present in some wastes. Since compost products vary significantly in their degree of freedom from biological, chemical or physical contaminants, the quality level of a compost product must be suited to the intended end-use of the product.

http://www.calrecycle.ca.gov/Organics/CompostMulch/CompostIs.htm