Composting is a great way to turn organic discards into rich, nutritious soil for plants to grow, which can in turn produce more food for people and animals. Composting can also reduce the amount of waste you produce, which has many flow-on benefits, such as paying less for council waste pickup, reducing methane emissions, and using less land for waste (which puts less total pressure on land and the cost of using it). Composting is best done by people who have some land to put a compost bin on. Worm farms can be used for people who do not have access to land.
What can go in compost? Anything that derives from living matter (organic material). Compost likes to have an appropriate amount of moisture–it shouldn’t be too moist that if you squeeze some compost you will get a drop out, but it shouldn’t be dry either. About a 40% moisture content is about right. Compost is also best aerated weekly. It is best to add in about the same amount of carbon-rich and nitrogen-rich materials. Carbon rich materials include food scraps, while nitrogen-rich materials include faeces, urine and garden trimmings. With garden trimmings, it is best to leave them in the sun for a few days to dry before adding in the compost. Every time something is added to compost that could attract pests, it should be covered with garden trimmings, soil, a hessian cloth or other material.
Putting faecal and urinal matter in the compost reduces water use, and avoids environmental impacts associated with sewage. The bacteria in compost will destroy any pathogens that may be attracted to fecal and urinal matter.
If you live in Sydney, compost bins can be bought from many local councils at a discount rate. For more information, see http://compostrevolution.com.au/.