Composting of Lawn and Farm Wastes
North Pole, Alaska, 1998
One of the more likely places to compost is on the farm. There is an abundance of organic waste, available land, the equipment needed for the process exists and there are numerous benefits which compost can add to the soil. This is especially important in Interior Alaska where soils are infertile. Compost as an organic amendment will help the soil retain moisture, increase nutrient availability and help to reduce diseases.
Another source of organic waste, which is a potential source in our urban community both from home owners and commercial lawn care operations, is grass clipping. Composting offers an alternative to dumping at the landfill which is becoming more expensive and even prohibited in many communities across the United States.
Who Initiated Program
For the composting process to proceed quickly the materials to be composted should have a carbon/nitrogen ratio of 30:1, a moisture content of 50% and a pH between 5 and 9. In this project this carbon/nitrogen ratio was obtained by mixing green grass clippings (the nitrogen source) with brome hay (carbon source) in a ratio of 1 to 4.
The material was initially piled in a windrow two feet high to allow for moistening and mixing with a tedder rake. Once the pile was thoroughly mixed and wet, it was piled with a front end loader to a height of four feet.
The material should be loosely stacked to allow as much space for air as possible between particles.
The windrow can be as long as you want but the pile height is critical. If the pile is too high, the weight will not allow for adequate aeration. If the pile is too small, the pile will tend to dry out. Moisture is critical for the decomposition process. If the pile is allowed to dry out, decomposition will stop. It may be necessary to water the pile every day for a week to keep the moisture level to the consistency of a wet sponge. Clear plastic visqueen was used to cover the pile to keep the moisture in. The clear plastic also allowed the sun to help warm the pile.
To determine the most effective way to create a composted product from lawn and farm wastes.
Alaska Science and Technology Grant
Results & Impacts
The compost is done when the internal temperature has dropped from above 140°F. to the temperature outside the pile. It should be dark and crumbly. The process can take from 14 days to a year. The process will go faster if the material to be composted is shredded, the pile is turned at least twice weekly, the moisture level is kept up and the pile is the critical height of four feet.
The nutrient levels of the compost are low so it can be used as a slow release fertilizer. The compost can be used as a soil amendment to improve texture. Apply one-half cubic yard per 100 square feet of soil incorporated into a six inch depth. Compost can be used as a mulch around trees. Apply a one inch layer of compost over the root zone. The compost should not come in contact with the tree trunk.
Another excellent way to use compost is in a potting soil mixture. Because compost usually has a high salt content which can damage plant roots it is important not to use pure compost. Mix 1/10 to 1/3 compost by volume with other amendments. The compost will also act as a slow release fertilizer.
Problems and/or Suggestions
To produce a better textured produce, wood chips can be added as a carbon source. In this experiment wood chips were added by volume in a ratio of one part wood chips, two parts grass clippings, and eight parts hay. The wood chips also helped to keep the piles aerated. By turning the piles daily the composting process was completed in 14 days.
Coordinator at time of project, 1998:
Call or write to:
North Pole Acres
North Pole, AK 99705