!44: How Does Composting Work? Understanding the Science of Compost

!±8± How Does Composting Work? Understanding the Science of Compost

Whether you are aware of it or not, there are many factors that are hard at work in your compost pile. The two most important factors in compost are:

• The amount and variety of organisms in the compost;
• The various components and their chemical make up

There are various micro organisms that have their own part to play in the chemical process of decomposing all organic materials. These include:

• Fungi - these are very small, however they carry out some of the most complex activities in decomposition. They survive on materials that are dead or dying and they take their energy from the process of breaking down those organic materials.
• Actinomycetes - these are somewhat similar to fungi; however they are a much higher form of bacteria. These little organisms are what produce that "earthy" smell in your compost pile. They work to free the carbon, nitrogen and ammonia from everything in the pile and turn the materials into an almost peat-like substance.
• Bacteria - they can survive on just about anything, living or dead. They are very sensitive to temperature and as the temperature of your compost pile increases or decreases, they either become very active or inactive.
• Macro-organisms - these are the little creatures that you can see with your naked eye - including snails, slugs, ants, worms, sow bugs, spiders, mites, nematodes and flies. These creatures work to transform your raw materials into compost by chewing, digesting, churning, grinding and sucking the materials.

In addition to these creatures, your compost requires other factors to work. These include the carbon to nitrogen ratio, the surface area exposed, temperature, moisture and oxygen.

Carbon and nitrogen need to have a certain ratio to be effective in compost. The carbon is in materials that are "brown", such as shredded paper and straw, while the nitrogen portion is things such as kitchen waste and grass clippings. Once you start adding things to your pile, you will see how important this ratio is for successful composting.

The surface area allows for more successful decomposition by your micro organism friends. The larger the area, the more room they have to work. Aeration is crucial because oxygen is the main requirement for decomposition. This means that you need to actually mix up your compost at least once per week to add in enough air. The entire pile should not be too wet (you should not be able to squeeze water from a handful of material). Temperature is very crucial as well. If your pile's temperature is too low, it will slow the rate of decomposition.