Everest Holmes, head of product development for Grozome describes his stringent quality control procedures and explains the roles of various microbes in promoting plant health.

Before any of batch of Grozome® compost is deemed finished, we randomly select 2 piles of the 8 to run microbial assay tests on them. If both samples pass the standard for biologically complete (and are within the acceptable standard deviation), we send a combined sample to a third party to perform DNA sequencing and soil biology pathways report.

Here are the results for Batch 13, currently available for sale here.

DNA Sequencing Results

Note: percentages reflect total populations, not biomass. 

Microbial Genera and Their Roles 

1. Streptomyces (6.9% AE): 

  - Function: Known for producing antibiotics that can suppress soil-borne pathogens. They also play a role in decomposing organic matter.

  - Implication: High presence suggests good disease suppression capabilities and enhanced organic matter breakdown.

2. Paenibacillus (3.2% AE): 

  - Function: Known for nitrogen fixation, plant growth promotion, and pathogen suppression.

  - Implication: Contributes to improved nutrient availability and plant growth, as well as disease resistance.

3. Bradyrhizobium (2.5% AE): 

  - Function: Nitrogen-fixing bacteria commonly associated with legume roots.

  - Implication: Enhances nitrogen availability, particularly beneficial in legume-crop systems.

4. Pseudomonas (2.4% AE): 

  - Function: Known for their plant growth-promoting and biocontrol properties, producing siderophores, antibiotics, and enzymes that degrade pathogens.

  - Implication: Supports plant health through growth promotion and pathogen suppression.

5. Mycolicibacterium (2.2%):

  - Function: Includes species involved in organic matter decomposition and potential bioremediation.

  - Implication: Enhances soil health through organic matter turnover and possibly detoxification of harmful substances.

6. Nocardioides (1.7% OA):

  - Function: Decomposers that break down complex organic compounds.

  - Implication: Contributes to nutrient cycling and soil organic matter maintenance.

7. Burkholderia (1.3% AE):

  - Function: Includes species with plant growth-promoting abilities and biocontrol properties.

  - Implication: Enhances plant growth and disease resistance.

8. Bacillus (1.3% AE):

  - Function: Known for their ability to produce antibiotics and promote plant growth.

  - Implication: Supports plant health through disease suppression and growth enhancement.

9. Mesorhizobium (1.3% OA):

  - Function: Nitrogen-fixing bacteria associated with legume roots.

  - Implication: Enhances nitrogen availability for legumes, supporting their growth and soil fertility.

10. Thermobispora (1.2% AE):

  - Function: Thermophilic bacteria involved in the decomposition of organic matter.

  - Implication: Enhances composting efficiency and nutrient availability.

11. Micromonospora (1.2% OA):

  - Function: Produces antibiotics and decomposes organic matter.

  - Implication: Supports disease suppression and nutrient cycling.

12. Sphaerobacter (1.2% OA):

  - Function: Thermophilic bacteria involved in the breakdown of organic matter.

  - Implication: Enhances composting processes and nutrient cycling.

13. Parageobacillus (1.0% AE):

  - Function: Thermophilic bacteria involved in organic matter decomposition.

  - Implication: Contributes to efficient composting and nutrient release.

14. Microbacterium (1.0% AE):

  - Function: Involved in decomposing organic matter and possibly promoting plant growth.

  - Implication: Enhances soil organic matter turnover and potential plant growth support.

15. Geobacillus (1.0% AE):

  - Function: Thermophilic decomposers.

  - Implication: Contributes to composting efficiency and nutrient cycling.

16. Sphingomonas (1.0% AE):

  - Function: Involved in bioremediation and organic matter decomposition.

  - Implication: Enhances soil health through detoxification and nutrient cycling.

17. Sorangium (0.8% AE):

  - Function: Produces secondary metabolites with antimicrobial properties.

  - Implication: Supports disease suppression in the soil.

18. Variovorax (0.8% AE):

  - Function: Involved in plant growth promotion and bioremediation.

  - Implication: Enhances plant growth and soil health.

19. Rhizobium (0.8% AE):

  - Function: Nitrogen-fixing bacteria associated with legume roots.

  - Implication: Enhances nitrogen availability, supporting legume growth and soil fertility.

20. Cupriavidus (0.8% AE):

  - Function: Known for heavy metal resistance and plant growth promotion.

  - Implication: Enhances soil health through bioremediation and plant growth support. 

Overall Effectiveness 

The presence of these microbial genera suggests that the compost extract has the potential to significantly enhance soil health and plant growth. The benefits include:

Nutrient Cycling and Availability

Genera like Paenibacillus, Bradyrhizobium, Mesorhizobium, and Rhizobium contribute to nitrogen fixation, enhancing nitrogen availability for plants.

Disease Suppression

Genera like Streptomyces, Pseudomonas, Bacillus, and Micromonospora produce antibiotics and other compounds that can suppress soil-borne pathogens.

Organic Matter Decomposition

Genera like Thermobispora, Sphaerobacter, and Parageobacillus help decompose organic matter, improving soil structure and nutrient availability.

Plant Growth Promotion

Genera like Burkholderia, Bacillus, and Sphingomonas have plant growth-promoting properties, enhancing overall plant health and productivity.

Soil Health and Bioremediation

Genera like Mycolicibacterium and Cupriavidus can contribute to soil detoxification and remediation of contaminants.