Compost Fundamentals

Compost Benefits & Uses

quality of composts

The nutrient value of composts varies widely, depending upon the nature of feedstock composted. If initial material contains grass clippings, weeds, or manure, it will be richer in nitrogen and other nutrients than if it contains mainly straw, litter, dirt or corn stalks.

The following analysis shows the ranges of values, on a dry basis, in which the chemical characteristics of most finished composts generally lie. These ranges vary because different initial materials will yield final composts of widely varying chemical characteristics.

Substance Percentage
by weight
Organic matter...............................
25.0-50.0
Carbon...............................
8.0-50.0
Nitrogen (as N)...............................
0.4- 3.5
Phosphorus (as P2O5).......................
0.3- 3.5
Potassium (as K2O)...........................
0.5- 1.8
Calcium (as CaO)...............................
1.5- 7.0

Composts also contain a great variety of micronutrients. Since organic materials for composting contain products of agriculture or horticulture, it is logical to expect these nutrients to be present in the compost. Experiments indicate that compost manures have beneficial effects greater than those to be expected from nitrogen, phosphorus, potash, and humus content alone.

Quality compost also contains many organisms necessary for soil health. Depending on feedstock, weather and type of process used, each batch will have different organisms. This composted organic matter, when applied to the soils provides a necessary source of energy and food for the soil organisms, as well as essential nutrients for plant growth.
Think of the soil not only as a physical and chemical substrate, but as a living entity. When making quality compost you can manage the soil organisms as a high value “mini-livestock.”

 

economic aspects

testing and judging condition of compost

quality of composts

benefits of compost

use of compost

Why Compost | Biology & Chemistry | Compost Needs
Composter's Needs | Benefits & Uses | Conclusion

Return to Whatcom County Composting

 
WSU Logo