Composting 101

Well i thought we were long over do for a composting how-to and i finally had the time to put it together.

How composting works:

In nature, organic wastes are broken down through a combination of biological and chemical processes. Biological agents like worms, insects, fungi, bacteria and other micro-organisms "chew up" the materials, which are further transformed by oxidation (exposure to air), reduction and hydrolysis (exposure to water).

For successful composting, you need:

*The right amount of water and air to keep the biological and chemical processes functioning.

*The right temperature. Ever notice how quickly things go 'bad' in warm - weather? For the purposes of composting, the warmer it gets, the better. In a cool environment, the composting process slows down. The internal temperature of a compost pile is also important. When the process of decomposition is at its peak, the compost will tend to generate quite a bit of heat. In a sense it's 'cooking'.

*The right C:N ratio. This is the proportion of carbon to nitrogen in your compost unit. This ratio will affect the speed of decomposition. Ideally, your C:N ratio should be thirty to one. Grass clippings, plant trimmings and kitchen scraps are high in nitrogen. Sawdust, straw, wood chips and dry leaves are high in carbon. A mixture of kitchen and yard waste should give you close to the ideal ratio.

*The right container you should use is a compost unit. You can build your own or buy one from your local hardware store or garden supply centre. Some municipalities offer composters at a special price, to encourage their residents to use them.

The three most essential features in a composter are:

A lid that protects the pile from rain and snow and allows you to control how much moisture gets in.


Holes or vents to allow air circulation.


A means of removing the final product.


Here are some design ideas:


A wire mesh bin with a hinged front panel.


A three-sided cement block bin with an open front that will allow you to turn the pile and remove the finished compost easily.


A circular unit made from chicken wire or snow fencing that can be opened up to collect the finished compost.


A wooden pallet or two-by-four box with a lid and spaces for ventilation.


A metal barrel or garbage can with holes punched in the side and the bottom removed.


For more advanced enthusiasts, a unit with several compartments can be used to manage compost at different stages - raw materials, active piles and finished product.


Put your unit in a level, well-drained, accessible area. If you live in a part of the country that has winter weather, make sure you can get to your composter all year round.


Add other organic materials in layers no deeper than l5 centimeters. Cover each successive layer of organic material with about 5 centimeters of ordinary garden soil. This contains micro-organisms that will accelerate the process: A layer of soil also helps to mask any odours.


Pour water onto the pile until it is about as moist as a wrung out sponge.


Turn the pile once a week to mix all the materials evenly and expose them to air.


Continue to add material as you go along. Always remember to cover new material with a layer of soil and to keep the pile moist.


A how-to link for building a bin: http://www.mastercomposter.com/equip/buildbin.html

When is Compost Finished?
The finished compost will take up only 25 - 40% of the space occupied by the original pile. When the individual materials can no longer be identified and the pile resembles dark rich soil, the compost is completed. It will smell sweet, woodsy, and earthy. It will crumble through your fingers.

From beginning to end, the composting process can take from 6 weeks to 2 years. Hot composting times will be much less than cold composting. Factors noted in the instructions above will determine how long the process takes. Everything matters -- how often the pile is turned, what materials went into the pile, the condition of the materials, moisture, adequate air, presence of insulation around the pile, size of the pile, etc.

If you add materials as you get them, instead of building batches of compost, you will find that after 6 months to two years, the inside and bottom if the pile, i.e., the matter you added first, has become compost. You may remove this from the bottom of the pile and use it. Return the rest of the materials to the bin or pile location to continue decomposing.

I hope this answered a few questions.As a side note 2 years ago i began using a 55 gal covered drum w/ holes for composting.When i needed to turn the pile i just tipped the barrel onit's side and rolled it around the yard....however this was too much work for this old stoner so i went with a simpler design:



after your pile starts to heat up it can get to between 110-120 degrees.


also i usually find a few twigs and stems left over in the pile when i need to get compost so i just sieve it with a window screen and end up with fine unadulterated compost:






Valuble links for further reading:

http://www.mastercomposter.com/

http://www.ces.ncsu.edu/hil/hil-8100.html

http://home.howstuffworks.com/composting.htm


(Edited by greenthumb420 at 10:16 am on Jan. 4, 2004)