Week One: Soils & the C:N Ratio
Week Two: Aerobic & Anaerobic Composting - Greens and Browns
Week Three: Microorganisms Involved in Composting
Week Four & Five: Composting with Worms
Week Five: Composting Graphs
2011 Master Composter Class information
2010 & 2009 Program
Program and Class Schedule (2010)
Vermicomposting (worm bin designs)
Amount of Water to Use on Newspapers for Vermicomposting
What is Compost?
Compost is broadly defined as the resultant material from aerobic breakdown by microorganisms of organic plant & animal materials. When decomposition is complete, compost has turned to a dark brown, powdery wet material called humus. It is dark, easily crumbled, and has an earthy aroma. The processes occurring in a compost pile are similar to those that break down organic matter in soil. However, decomposition occurs much more rapidly in the compost pile because the environment is ideal for the microbes to do their work (Figure 1).
Figure 1. Illustration of the complex processes and associations happening in a compost pile
Why make compost?
Most people often have difficulty disposing of leaves, grass clippings and other garden refuse, particularly in urban areas. These byproducts of the garden and landscape can be turned into useful compost with no more effort than it takes to bag and haul them away. Home composters avoid hauling or utility costs associated with centralized composting facilities and end up with a valuable soil conditioner or mulch for the landscape and garden. In Oregon, there are over 40% of materials that go to the landfills that can be composted thereby reducing need for more and more landfill space.
The value of compost
Good compost consists primarily of decomposed or partially decomposed plant and animal residues, but may also contain a small amount of soil. Compost improves both the physical condition and the fertility of the soil when added to the landscape or garden. It is especially useful for improving soils low in organic matter.
Organic matter in compost improves heavy clay soils by binding soil particles together into "crumbs or aggregates," making the soil easier to work. Binding soil particles also helps improve aeration, root penetration and water infiltration and reduces crusting of the soil surface. In sandy soils, additional organic matter also helps with nutrient and water retention. Compost also increases the activity of soil microorganisms that release nutrients and other growth-promoting materials into the soil.
Although compost contains nutrients, its greatest benefit is in improving soil characteristics. You should consider it as a valuable soil amendment rather than a fertilizer, because additional fertilization may be necessary to obtain acceptable growth and yields.
To know more about composting and the various processes that make it happen including materials that you can use for composting, please visit the following resource links