Pile Maintenance

Maintenance of the compost pile involves turning the pile and adding water to maintain conditions conducive to the composting process. If the pile is not turned, decomposition will occur, but at a slower rate. The following maintenance procedure will yield compost in the shortest time.

Turning a Compost Pile

Turning a compost pile weekly can yield compost in one to two months with the right combination of materials and moisture content. Without turning, decomposition takes six months to two years. Excellent quality compost can be made either way. When selecting a composting method, consider economy, neatness, permanence, need for finished compost, and time available for maintenance.

In a pile constructed according to the method described here, the pile temperature will increase rapidly and soon reach about 110 degrees Fahrenheit. After about a week, the pile should be opened to the air and any compacted material should be loosened. Then the pile should be reconstructed; material previously on the top and sides of the pile should be moved to the center.

Second Turning

At the second turning (after about another week), the material should be a uniform coffee-brown color and moist. The relatively non-decomposed outer layer can be scraped off and turned back in to the center of the pile. The center material should be spread over the outer layer of the reconstructed pile. By the third turning, the original materials should not be recognizable. At each turning, the moisture content should be checked using the squeeze test. Squeezing a handful of compost you should be able to make some water droplets appear around the edges. If you can't squeeze some water out of the compost it is too dry. However, if more than four drops appear it is too wet. Water or moisture absorbing materials should be added, as indicated.

Pile Temperatures

During the first few weeks of composting, the pile should reach a peak temperature of about 140 degrees Fahrenheit. If temperatures surpass 140 degrees Fahrenheit, the pile should be turned to cool it off. Extremely high temperatures can kill many beneficial organisms. If the pile does not reach at least 120'F, more nitrogen or water may be needed. Cold weather can also prevent the pile from heating. Piles that give off strong ammonia smells contain too much nitrogen, and may need more high-carbon ingredients.

Simple carbohydrates and proteins provide most of the energy for the initial, rapid stages of decomposition. When the more resistant materials, such as woody fibers and cellulose, become the main food sources, the activity in the pile will slow down. Less heat will be produced, and the temperature will begin to fall to about 100 degrees Fahrenheit. Even after the temperature falls, the compost will continue to stabilize slowly.

The compost will be finished when the pile cools off and decreases to about 1/3 of its original volume (depending on the original ingredients). It will be dark, crumbly, and have an earthy odor. The C:N ratio will be less than 15:1, approaching the value of humus in soil, and the temperature usually will be within 10 degrees Fahrenheit of ambient air temperature. Unfinished compost can be toxic to plants, especially to seedlings and newly established plants. Therefore, compost must be allowed to decompose thoroughly before use.