Originally Published In The Deseret News -- Thursday, November 13, 1997
Larry Sagers Is A Horticulturist With The Utah State University Extension Service.
Last week's column covered the need to add organic matter to the soil. It is one of the few components that can be changed enough to make a significant difference in soil improvement. Even so, it is not a perfunctory effort that can be accomplished by throwing out a few bags of this or that every few years. Large volumes of material that can be added on a regular basis are needed to make improvements in garden soil.
Composting is the natural process that breaks down all kinds of organic materials into rich soil-like material. Finished compost is an excellent soil amendment that improves soil structure as it binds sand, silt and clay particles together. Compost also adds some nutrients although these are mostly tied up in the organic matter so they are available very slowly. Organic materials of all kinds will be break down eventually, under the proper environmental conditions. The process is speeded up dramatically with proper management of the organic materials and composting environment.
All compost requires certain basic ingredients. These include organic matter, microorganisms and the right balance of carbon, nitrogen, water and oxygen. Each component is essential to create the desired end product.
Organic matter is the raw material from which all compost is created. Successful composting requires abundant raw material because the composting process drastically reduces the volume of material as it goes through the process. Suitable materials for composting include corn stalks and other garden plants, grass clippings, pruning waste and tree leaves. The last component or the leaves are the most important this time of year because they are an ideal soil improvement product. They are readily available, the price is right (free) and they have no weed seeds. Nevertheless, understanding more about composting will help create this magic black gold more successfully.
For composting to occur a proper balance must exist between the carbon and the nitrogen components of the dead plant materials. Ideally this ratio should be about 30:1. Some common carbon to nitrogen ratios by weight, of various organic materials are as follows:
Sawdust has a high C:N ratio, while animal manures have a low C:N ratio. Achieving the ideal ratio for composting is done by combining high and low carbon materials, such as dry tree leaves with fresh grass clippings or manure. Nitrogen is added to high carbon materials by using fertilizer like ammonium sulfate.
I prefer the sheet composting method for leaves. They do not require hot composting because they usually have no pathogens from diseases that have killed the plants and no weed seeds. They are easily tilled into the ground this fall and will easily decompose by next spring. Add some nitrogen fertilizer to enhance the process and magical compost starts forming immediately.
The smaller the particle size, the faster the organic materials will decompose.
If you prefer constructing a compost pile rather than spreading the materials on the garden, form the pile in layers, alternating yard wastes; a nitrogen source, if needed, and soil. Form the first layer from 6-10 inches of organic materials, with coarse, dry materials on the bottom. Add 2 inches of manure or one-half cup ammonium sulfate on a 5-foot by 5-foot compost pile. Follow with one inch of soil. Repeat layers as long as organic matter is available. Water each layer as it is added, and add additional moisture as needed to keep the pile moist but not wet. A pile 4 to 5 feet in diameter and 4 to 5 feet deep, should reach 130 to 160 degrees F in the center. Turn the pile with a pitchfork or shovel at least once or twice a month to add oxygen and to bring outer contents to the center for heating. Start a new pile when compost becomes too tall to work by hand.
- THE DAVIS COUNTY MASTER GARDENER PROGRAM - It's time to register for the Winter 1998 Master Gardener Volunteer Training Class, sponsored by Utah State University Extension Service. Call 451-3204 for an application form or come to the USU Botanical Gardens, 1817 N. Main, Farmington for application forms. The classes will be every Wednesday and Friday morning from 9:30-11:30. This series will start on Wednesday, Jan. 7 and run through Friday, March 13. The classes cost $75 and are open to anyone on the Wasatch Front who is willing to donate 40 hours of volunteer time at the USU Botanical Gardens in Farmington in 1998. Upon completion of the volunteer hours, $40 will be refunded.
*****
Additional Information
Compost
For composting to occur a proper balance must exist between the carbon and the nitrgen components of the dead plant materials. Some common carbon-to-nitrogen ratios by weight are:
Material C:N Ratio
Livestock manure 10-12:1
Table scraps 15:1
Grass clippings 20:1
Fruit wastes 35:1
Leaves 40-80:1
Paper 170:1
Sawdust 511:1
Wood (pine) 723:1
© 1998 Deseret News Publishing Co.