In Oklahoma, yard trimmings and grass clippings can make up 15 to 25 percent of a community’s waste. The costs of collecting and transporting yard waste and the subsequent landfill tipping fees may be a considerable portion of a community’s waste management budget. These costs may be reduced if communities encouraged and practiced backyard yard waste composting.
Yard wastes, especially grass clippings, are usually high in nutrient content. When yard waste is composted, bacteria use air and water to break down plant materials into nutrient-rich compost. These nutrients can be beneficial to soils, plants and trees in the yard when applied as mulch or a soil amendment.
Compost systems can be simple and slow such as a heap or pile, which is turned occasionally during the year. A more structured and complex system requires containers, more turning and produces finished compost in a few months. In compost piles, water is added to green and brown vegetation layers.
As decomposed plant material, compost is an excellent soil amendment. Compost can loosen clay soils, help sandy soil retain moisture and nutrients and retain soil moisture when used as a mulch. Beneficial bacteria and organisms in compost assist plants in absorbing nutrients. Thus, natural materials are recycled in a home yard environment.
What is Compost?
Compost is a natural dark brown humus-rich material formed from the decomposition or breakdown of organic materials such as leaves, grass clippings, vegetation, vegetable food scraps and twigs. Bacteria, worms, fungi and insects need water and air to use the organic materials as food and decompose them.
What is the Procedure to Make Compost?
Organic materials are placed in alternating green and brown layers in a container, bin or pile. Alternating green and brown layers of material help assure the correct carbon and nitrogen amounts. With water and air, bacteria and insects use the materials as a food and energy source. The bacteria need water to live and grow. This process generates heat from 140 F to 160 F. Aeration is done by turning the container or pile of material. The more turning, the more air the bacteria have available and the faster the process works. When the temperature decreases, the process is complete.
How is a Compost Bin Made?
Bins may be made in various sizes and with a variety of materials. The following easy steps describe compost pile construction:
1. Construct a confining perimeter 3 feet to 5 feet in diameter and 4 feet high. Materials may be concrete blocks, wire mesh, boards, old pallets, other fencing material, barrel or garbage can with holes for air.
2. Layer green (wet) and brown (dry) vegetable matter (one part green to three parts brown).
3. Wet thoroughly, then sprinkle with water periodically.
4. Turn every week to speed the decomposition process.
How Long Does it Take Compost
The time of completion will vary according to the type and amount of materials used, the climate, the size and type of bin or pile used and the amount of aeration or turning of the pile. With the correct carbon-to-nitrogen ratio, water and air, the compost should be ready to use in four to six months. If the pile is turned more frequently, the compost should be ready more quickly. The smaller the individual pieces of material in the pile, the more surface area the microorganisms have and the faster the materials will decompose. Shredding or chipping branches decreases the decomposition time.
When is the Compost “Done?”
Compost is ready when the temperature of the pile falls to ambient levels, the material is dark, crumbles easily, pieces are small and there is no odor.
How can the Process be Sped Up?
Mixing frequently provides more air for the bacteria. Keep the material moist with soaking about once a week. Break the materials into smaller pieces.
What can be Composted?
• Most yard waste such as grass clippings, leaves, twigs and excess vegetation.
• Food scraps without fat.
• Twigs or chipped branches.
• Coffee grounds, tea leaves.
What cannot be Composted?
• Large branches.
• Fatty foods and grease, meats, dairy products and fish.
• Synthetic products such as plastics.
• Diseased plants.
• Weeds and vegetables that produce abundant seeds.
• Pet or human waste.
• Recycle natural materials.
• Reduce amount of chemical fertilizer used.
• Reduce amount of material going to landfills.
• Reduce landfill tipping fees for individuals or communities.
• Prolong landfill life.
How can Compost be Used?
• Improve soil structure and texture.
• Increase water-holding capacity of sandy soil.
• Loosen clay soil and improve drainage.
•Add nutrients to improve soil fertility.
• Aid erosion control.
• Potting soil.
• Mulch around landscape plants to retain moisture.
Problems that may be Encountered (Trouble Shooting)
|Pests- rats, raccoons, etc.||Meats or fatty foods||Remove and omit meat products
Cover pile with soil or sawdust
|Low pile temperature||Pile too small|
Not enough air
Not enough moisture
Not enough nitrogen (N)
Weather too cold
|Need bigger pile
Add water when turning pile
Add greens, N sources such as fertilizer and grass clippings
Insulate with straw or plastic
Reduce water, protect from rain, turn more frequently
|High pile temperature (+140 F)||Too big|
Not enough air
Turn more frequently
|Rotten Odors||Not enough air|
|Turn more frequently, add coarse material such a straw
|Ammonia||Too much nitrogen |
Need more carbon
|Add more browns, less greens
Add straw, paper or cardboard
If you need further information or assistance, please contact the local county Extension educator.
Ag in the Classroom Curriculum, Grades 3-4, Lesson S1- Composting
L-251, “Recycling Yard Waste, “Don’t Bag It” – Mulching with Wood Chips”
L-252, “Recycling Yard Waste, “Don’t Bag It” – Leaf Composting”
L-253, “Recycling Yard Waste, “Don’t Bag It” – Lawn Care Plan”
Publications Web Site: osufacts.okstate.edu
The Rodale Book of Composting by D.L. Martin and G. Gershuny, Eds., Rodale Press, Emmaus, Pennsylvania
Compost Bin Styles
1. Garbage can or barrel – with holes in bottom and in rows about 4 to 6 inches around sides.
2. Commercial – many varieties usually about the size of a 30-gallon garbage can, found at home supply stores.
3. Three-bin turning units are made so the compostable material can be easily transported from one bin to another, reducing the time to produce the compost. They can be made out of a variety of materials.
b.Wood with wire sides
4. Holding units (for easy passive composting) can be made from many materials, require no turning and are slower to produce compost.
c.Posts and chicken (or other type) wire
d.Posts and snow fence
Assistant Extension Specialist