Composting - Nature's Recycling

Composting – Nature’s Recycling

Composting is an invaluable part of today’s green lifestyle. It also offers the satisfaction of receiving a gift of beautiful “brown gold”, nutrient rich soil, at the end of the process. 

Studies have shown that individual home composting can divert an average of 700lbs of waste from landfills per year. Food waste and yard clippings represent approximately 30% of the waste stream in the US, so recycling these materials in a composting bin can make a significant change to our impact on the environment. 

Composting is basically making use of the decomposition process that occurs in nature whenever a plant dies. Microorganisms and invertebrates attack the remains of the plant and break it down to become natural humus. This natural decomposition can be encouraged in the backyard environment by providing ideal conditions in a composting bin. The process requires oxygen and water to create the perfect conditions for speedy decomposition. A dry, untended compost pile will decompose, but very slowly. Active composting, however, can be completed in around 6 weeks. 

There are 3 key components necessary to create the ideal composting environment: 

The decomposition process uses up all of the available oxygen in the center of the pile, so it needs to be “turned” regularly to allow oxygen to be replaced and bring new material into contact with the active microbes. There are excellent composting bins available that accomplish this process, utilizing a rotating drum on a fixed frame that can be easily turned allowing internal fins to break up the pile and provide good aeration. 

The ideal compost moisture content is between 40 and 60 percent. This represents the moisture content of a well wrung out sponge. Too little moisture will result in the composting process slowing down as the microbe activity will become dormant. Too much moisture will hinder aeration and cause a bad odour to be emitted from the pile. A healthy compost pile will have a sweet earthy odour. 

3) Carbon/Nitrogen Ratio

Carbon is generally referenced as “brown” material and Nitrogen as “green” material. The ratio between the two will have a significant impact on the health of the pile. The bulk of a compost pile should be “brown”, with just enough “green” to aid the decomposition process. The ideal ratio is 30 parts carbon (brown) to 1 part nitrogen (green). Too little green material will slow the process and too much may cause the generation of ammonia gas and unpleasant odours. 

Examples of Brown material are:

Cereal Boxes, Coffee Filters, Egg Shells (crushed), Dry Leaves and Grass, Newspaper (shredded), Brown Paper Bags (shredded), Saw-Dust, Straw (chopped). 

Examples of Green material are:

Grass Clippings, Tea-Bags, Leaves (green), Fruit or Vegetables, Bread, Pasta (cooked), Rice (cooked), Seaweed, Garden Weeds (not bearing seeds or pervasive root structures). 

Examples of materials not appropriate for compost piles:

Bones, Cheese or other Dairy Products, Fish, Meat, Rhubarb Leaves, Fats (oils, grease, etc.), Diseased or insect-infested plants, Treated Paper (slick or glossy). 

With the above components in place a healthy compost pile will generate heat as the microorganisms decompose the organic material. An efficiently operating compost pile will generate temperatures between 90º and 140º Fahrenheit. The process will naturally slow down in the winter months in cold climates, however some microorganisms like cool temperatures so decomposition will continue. It is not unusual to see steam coming from an active pile in cold weather. 

There are many different ways of operating a compost pile. Simple enclosures can be built on the ground and various different styles of composting bin can be purchased commercially. The combination of food waste and yard waste can create a problem with rodents in some areas but an enclosed bin or raised bin may be advisable. Many municipalities offer curbside yard waste collection and transport the material to central composting sites. However, this involves the use of heavy equipment and fossil fuels, so individual backyard composting offers a significant environmental and economic benefit.

It’s Eco Time 2008