Soil Foodweb Assays

Our primary service is to offer tests developed by Dr. Elaine Ingham and her staff to analyze the microorganism groups most essential to the health of any soil. These include:

TB: Total Bacteria: (total biomass of all bacteria, active or dormant)
Bacteria promote plant health in many ways, such as by digesting soil nutrients in forms that are not available to plants, thus enabling nutrient conversion into plant available form. Optimal range varies according to crop, climate and season; if the value is not within this range, bacterial inocula or foods may be required.

TF: Total Fungi: (total biomass of all fungi, active or dormant)
Fungi also process nutrients from forms that plants could not access without help. In addition, healthy fungi create networks of filaments which transport nutrients to where they are most needed. The optimal range of biomass varies according to crop, climate and season, and may require amendment if outside this range.

AB: Active Bacteria: (total biomass of active bacteria)
Only the bacteria which are currently metabolizing organic compounds are directly nourishing the plants; if this portion is too low, bacterial foods may stimulate the dormant population.

AF: Active Fungi: (total biomass of active fungi)
As with bacteria, only those fungi which are currently growing and metabolizing are directly nourishing the plants, so the dormant part of the population may need feeding if the activity is low.

Prots: Protozoa: (numbers of individual Flagellates, Amoebae, and Ciliates)
These single-celled organisms eat bacteria and excrete plant available nitrogen in the form of ammonium, making them essential to healthy plant growth. One morphological group, the Ciliates, prefer anaerobic bacteria, so a high ciliate population may indicate anaerobic conditions which need to be addressed.

Nem: Nematodes: (numbers of individuals and identification to genus and function)
A very large group of very small worms, found everywhere on Earth. Some soil-dwelling species cause significant crop damage, some prey on other nematodes, and most graze on bacteria and fungi, excreting ammonium. Diverse nematode activity is a sign of healthy soil, and beneficial to any plant because they cycle nitrogen into plant available form.

VAM: Mycorrhizal Colonization: (percentage of root sample colonized by beneficial fungi)
Over 90% of all plants on Earth form symbiotic relationships with mycorrhizal fungi. These fungi increase the nutrient uptake capacity of the plant and protect it against pathogens. They are also sensitive to many toxins in chemical pesticides and inorganic fertilizers, making them a valuable indicator of overall soil health. We determine what percentage of your roots are colonized, and also look for signs of disease and other damage.

QA: Qualitative Assessment: (Bad, Poor, Adequate, Good, Very Good, or Excellent)
In this fast evaluation, a visual scan of populations determines whether or not bacteria and fungi are present, and provides the approximate range of numbers seen. It can also detect the presence of protozoa and nematodes, although it does not verify their absence if not detected. Does not provide precise counts or calculate biomasses of organisms. It is mainly used to assess the progress of efforts to remedy problems identified in earlier, more thorough testing.

E. coli: Escherichia coli bacteria: (number of Colony Forming Units detected)
These common intestinal bacteria have some disease-causing strains, and can indicate other harmful bacteria may be present. We evaluate the number of Colony Forming Units per gram of compost or milliliter of compost tea, to let you know if levels are within or above accepted limits for agricultural fertilizers.

General Assays

EC: Electrical Conductivity: (high conductivity indicates high salt levels)
This test indicates the salinity of soils and composts, to let you know if salt levels are acceptable or potentially harmful.

pH: Acidity or Alkalinity: (low pH indicates acidity; high pH indicates alkaline conditions)
Different crops have different requirements for soil acidity or alkalinity, and the pH is influenced both by the mineral content and the biology in the soil. This test allows us to advise you on how to supplement your soil to correct the pH for best growth of your crops.

Leaf Organism Assay:
This test determines the effective coverage of organisms on the leaf surface, very useful for before and after comparisons of foliar applications of Compost Tea. Adequate coverage of leaf surfaces helps to reduce disease and pests.