Purchasing Compost & Mulch
| Indicator | Quality Standard for Finished Compost | |
|---|---|---|
| Visual | All material is dark brown (black indicates
possible burning). Parent material is no longer visible. Structure is mixture of fine and medium size particle and humus crumbs. |
|
| Physical | Moisture: 30-40%, Fine Texture (all below 1/8" mesh) | |
| Odor | Smells like rich humus from the forest floor; no ammonia or anaerobic odor. | |
| Nutrient | Carbon:Nitrogen Ratio | <17:1 |
| Total Organic Matter | 20-35% | |
| Total Nitrogen | 1.0-2.0% | |
| Nitrate Nitrogen | 250-350 PPM | |
| Nitrite Nitrogen | 0 PPM | |
| Sulfide | 0 PPM | |
| Ammonium | 0 or trace | |
| pH | 6.5-8.5 | |
| Cation Exchange Capacity (CEC) | >60 meq/100g | |
| Humic Acid Content | 5-15% | |
| ERGS Reading | 5,000-15,000 mS/cm | |
| Microbiological | Heterotrophic Plate Count | 1 x 108 - 1 x 1010 CFU/gdw |
| Anaerobic Plate Count | Aerobes: Anaerobes at 10:1 or greater | |
| Yeasts and Molds | 1 x 103 - 1 x 105 CFU/gdw | |
| Actinomycetes | 1 x 106 - 1 x 108 CFU/gdw | |
| Pseudomonads | 1 x 103 - 1 x 106 CFU/gdw | |
| Nitrogen-Fixing Bacteria | 1 x 103 - 1 x 106 CFU/gdw | |
| Compost Maturity | >50% on Maturity Index at dilution rate appropriate for compost application. | |
| Compost Stability | <100 mg O2/Kg compost dry solids-hour | |
| E. coli | < 3 E. coli/g | |
| Fecal Coliforms | <1000 MPN/g of dry solids | |
| Salmonella | < 3 MPN/4g total solids | |
Prepared by: |
Organic Ag Advisors P.O. Box 942 North San Juan, CA 95960 (530) 292-3619 |
BBC Laboratories, Inc. 1217 North Stadem Drive Tempe, AZ 85281 (480) 967-5931 www.bbclabs.com |
Last updated: August 29, 2008