Compost Process and Testing

What is the City of Fayetteville Permitted to Compost?

We are permitted through the State of Arkansas to compost organic waste, which includes yard waste and food waste.


How is the Compost Mix Made?

The compost mix that is used here in Fayetteville mainly consists of the yard waste that is collected through the curbside program and other grass and leaves brought into the site by the public. We have also started collecting organic waste from three of Fayetteville’s Public Schools and the University of Arkansas. This organic material is also included in the compost mix.


Composting Process Start

A 30:1 ratio of carbon (brown material, such as dead leaves) to nitrogen (green materials, such as fresh cut grass) is ideal for composting. These materials are already rich with bacteria and fungi working to decompose the organic material when it comes to our facility. To quick start this process, we grind up the yard waste into a smaller particle size. We add air by turning the rows with our row turner and try to keep the piles moist through accumulated rainfall. Then, we let the microbes do their thing.


Ever-Changing Mix

This mix changes depending on the time of year. In the early months of the year, the mix is primarily dead tree limbs. In the spring and summer, the mix consists largely of grass clippings, along with brush and other clippings. In the fall, the mix consists of a large dose of leaves along with a little amount of grass clippings.


Weather's Effect on the Composting Process

Weather can effect amount of material we collect, as certain storms, draught conditions, and higher annual rainfall changes what comes into our facility. Drought conditions can also affect the composting process, as our facility relies on rain water to water the compost rows. The compost rows work best at about 60% moisture. In normal years, we receive 48 inches of rain, which allows for compost rows to "cook" very well. In drought conditions the microbes have a hard time working and the process can take longer to make finished compost.


Ours is Classified as Garden Compost

  • Medium to high mature organic matter 
  • Moderate to high nutrients and nutrient release potential 
  • Low carbon to nitrogen (C:N) ratio 
  • Moderate to moderately high salinity 
  • Low ammonium (NH4) to nitrate (NO3) ratio

Usage

Compost of this quality is good for all-purpose garden and greenhouse usage. Mixing the compost into a good topsoil will help increase the soil organic matter content and boost soil fertility. The compost by itself is not recommended for growing plants (i.e., it is not suitable for use as potting soil), but should instead be mixed in at least a 50:50 ratio with soil.


Lab Results 2022 - Midwest Laboratories, Inc.