|Composting is a great way to reduce
waste created in the home and utilize it instead of sending it to a
The product of composting is an excellent nutrient-rich material that
be used to fertilize gardens and trees- improving productivity and
in your garden while saving you money on fertilizer.
A garden that is fertilized with composted materials can better hold oxygen and water, drain more efficiently, and produce plants with fewer insect and disease problems. Composted humus promotes the growth of beneficial microorganisms in soil, and discourages harmful ones.
Different composting methods have been developed to best meet environmental conditions (eg: humid/tropical, dry/arid). Special considerations, which are described below, need to be made to compost effectively in arid environments where a lack of ambient humidity may desiccate organic matter before it has time to decompose.
|An assessment should be made
before settig up a compost pile, to
determine if composting is even a possibility. Reducing waste is one
reason why people compost, however, most people compost in order to
create fertilizer that improves garden productivity. The main
considerations for composting in an arid environment are 1) time, 2)
effort, 3) sufficient water. As shown below, the no-tending method
require very little time, but the composter may encounter difficulties
if the pile is not given any attention (see Troubleshooting below). If that is
the case, the
composter must determine if the payoff is worth the time needed to tend
the pile. If the pile is tended, some effort is required. It is
understood that many people are busy with work and other household
chores and mixing a composting pile may not be a priority. Thus, if
the no-tending composting pile does not work, then, once again, the
user must weigh effort versus payoff and decide if composting is
appropriate. The third consideration, having sufficient water, is
important in an arid environment. Obviously, it is not going to be
appropriate to compost if water is needed, yet scarce. Keep in mind,
however, that dirty water from the kitchen (dishwater, for example) and
urea can be used.
Composting is the process of breaking down and decomposing organic matter. Microorganisms in the pile feed on the material that you put into the compost, and in return give off CO2, water, heat and humus. Humus is the stable organic end product that holds the nutrients that can then be used in your garden.
The microorganisms that do the composting work are bacteria and fungi. The fungi break down the tougher debris in the compost pile, allowing the bacteria to continue decomposing the broken down material.
These microorganisms in your pile survive on the organic ingredients or your compost, but they need certain conditions to survive and work most efficiently. Moisture is an important element; compostpiles should contain 40-55% moisture, like a wrung out wet sponge. Too little moisture desiccates the microorganisms, and too much drowns them. Temperature is anther important aspect too. Though there is a range of temperatures that all the different organisms thrive at, the pile should not reach above 65°. Temperatures below 55° don’t kill the pathogens that are unsanitary to humans, but lower temperature composting is effective also, it just takes longer.
The bacteria live on the contents of the pile, but the actual active “feed” is the carbon and nitrogen that is contained in the organic matter, along with the oxygen necessary for aeration. This is what the microorganisms use to decompose the compost. The ideal mixture for your compost pile is to have a 30:1 ratio for C:N, but this does not need to be a precise measurement, and can be judged on the heat and smell of your compost- see below under How do I maintain it?
|Composting is a great way to deal
scraps, yard waste, and animal manure. These things are all great
to a successful compost pile, and add different nutrients to the
Most kitchen waste is great to throw in, including fruit and vegetable
egg shells, coffee grounds and filters, graywater, corn cobs and more.
Kitchen waste is usually high in moisture, which makes it and important
component in aird-environment composting.
Dairy products can be composted, but should be buried in the pile to
the smell that they generate, which may attract animals. Fatty
like meat and oils should not go in your compost pile.
|Corncobs||Dog and cat feces
||Breads and grains
|Your compost pile should be located in a level, well drained area with ample shade to protect it from the sun. This will help it retain moisture - a potential problem in arid environments. Put the pile close enough to the kitchen, so that it will be convenient and used regularly.|
|The equipment for simple composting is minimal and based primarily on how you choose to compost. Throwing compost into an easily accessible pile is the lowest maintenance option. In that case, the only tools necessary are a shovel or stiff-tined fork for turning and removing compost. To ward off unwanted pests (animals, large birds) it is a good idea to protect it using some type of fence. Alternatively, you could build a wire-mesh box, which not only protects it from animals, but makes it easier to move around when full. The drawback to confining it is that then the compost does not have contact with the soil, which provides microbes, worms and bacteria to speed up the process.|
|One method of composting entails
organic matter into a wire mesh box, and is classified as a “hot and
method that will produce compost from a cubic meter pile within a few
It does require it turned several times a week, which is done by mixing
with a stick or shovel. As turning does lead to dehydration, and thus
of the decomposing process, in arid environments, monitor the effects
pile intervention. If the compost is drying up, a passive approach can
taken, though composting time is much longer (up to a year). The
is based on 1) how much waste is produced and needs to be managed 2)
conditions (ie: humidity) 3) quantity of compost needed and 4) the
of the composter.
Regardless of whether an active or passive approach is adopted, the compost should be checked for moisture periodically, important in arid regions. As mentioned, it should be as moist as a wrung-out sponge. If necessary, add water to maintain the appropriate moisture level. In particularly parched areas, using dirty dishwater or adding urea are effective water-saving options.
Compost with lots of kitchen scraps does have the potential to attract flies and animals. The box method, as mentioned, should discourage animals. To ward off flies and insects, be sure to cover new organic matter with about 8 inches of old compost.
||Not enough moisture
|Nothing is happening
||Not enough nitrogen
Not enough oxygen
Not enough water
||Not enough carbon
The organic matter is thoroughly decomposed and ready for placement when the material is brown, crumbly, and earthy-smelling. If it is not fully broken down (material is still somewhat recognizable), then it should be allowed to further decompose, or be separated out.
The humus can be used on vegetable gardens and trees. If little organic matter is present in the native soils, a two to three inch layer of compost should be worked into the top six inches of soil. Following the first year, only ½ inch of compost is necessary to maintain soil quality.
For information on other methods (windrow, closed bin, artificial aeration, etc.) and more information, here are more resources:
- Numerous alternate methods and specific case studies presented.
- Easy-to-read brochure on composting, with specific information on mulching, soil incorporation and earthworm compost.
|Waste stoppers- Quick look at composting from the Gould League of Victoria in Australia.|
- In-depth information, covers the use of additives (lime, ash,
to improve composting and decomposition rates.
|Compost Guide - Though this is
site set up to sell composting bins and supplies, the information that
offers it is a good resource for composters.
and composting - Brief composting overview.
University of Agriculture, Philippines - Comprehensive study,
methods and advantages and disadvantages of each listed.
web resources - An overview of
||Master Composter - In depth information, includes a message
Campbel, 1998, Let it Rot!: The Gardner's Guide to Composting (third edition), Storey Communications, Inc.
|Dickson, Composting to Reduce the Waste Stream: A Guide to Small Scale Food and Yard Waste Composting, NRAES-43, Natural, Resource, Agriculture, and Engineering Service (buy it at NRES ).|
|Gershuny and Martin (editors), 1992, The Rodale Book of Composting: Easy Methods for Every Gardener, Rodale Press, Inc.|
|Taylor, Taylor and McCosker, 1994, The Compost Book, Robert Hale Ltd|
|Vance, 2001, Backyard composting: Simple, small-scale methods, Cooperative Extension Service, University of Wyoming; [Rev. ed.] edition|