Compost Quality Testing

According to Woods End Laboratory they divide the testing of composting and compost into 3 categories:
  • Source Materials - "Pre-Compost State": Tests to characterize ingredients and mix recipes to establish the process.
  • Composting - "Active State": Tests to manage quality during the process and the timing for completion.
  • End Product - "Completed State": Tests to evaluate quality and properties of the end-product, such as nutrient value, stability, disease suppression, microbial hygiene.

Classification by Woods End Laboratory

Woods End Laboratory classified the City of Fayetteville compost in 2015 as described below.

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


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.