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Soil Biology

Soil microbiology is the microscopic community of organisms that play a vital role in determining productive soil characteristics and a healthy habitat for plant growth and long term establishment. The most productive soil systems have balanced populations of flourishing organisms, including bacteria, fungi, protozoa and nematodes. Bacteria and fungi break down and consume the organic matter and mineral content of soils, creating a storehouse of nutrients that are released slowly over time. Predatory organisms, such as protozoa and nematodes, consume the bacteria and fungi, releasing nutrients into the root zone of your plants naturally. They consume and/or out compete disease-causing organisms along the way, helping manage pathogenic populations and reduce monetary loss from infections.
~ Reduced water usage
~ Improved nutrient cycling
~ Increased drought resistance
~ Deeper root growth
~ Improved soil structure (less compaction)
~ Increased disease resistance
Succession is the process of change in the species structure of an ecological community over time. A plant community gradually or rapidly replacing another can result from developmental changes in the ecosystem itself; or from disturbances such as wind, fire, volcanic activity, insects and disease, or harvest. Different plants require different ratios of fungi and bacteria, based on their successional growth traits. The biological approach seeks to match crops with their ideal soil habitat and associated microbial communities. Some plants are naturally acclimated to fungally-dominated forest soils; others are acclimated to grasslands that are more bacterially-dominated. The biology in the soil can enhance or impede plant growth based on the symbiotic or antagonistic relationships between microbes and plants. Conditioning the soil’s biology to compliment a specific crop will increase nutrient uptake, and can give the desired crop an edge over weeds they try to compete against.
Broccoli/Cabbage (Strongly bacterial)
Row Crops/Tomatoes/Grasses (Slightly bacterial)
Berries* (Equal bacteria and fungi)
Broadleaf Trees/Shrubs/Vines (2-10 times more fungal) [Note: Grapevines, blueberries (and other Ericaceous berries and shrubs), kiwi, and snowbrush are considered to be in the shrub/vine category due to their fungal needs.] Conifers (100+ more fungal than bacterial)
Compost is decayed organic material

Modern, methodical composting is a multi-step, closely monitored process with measured inputs of water, air and carbon- and nitrogen-rich materials. The decomposition process is aided by shredding the plant matter, adding water and ensuring proper aeration by regularly turning the mixture. Worms and fungi further break up the material. Aerobic bacteria manage the chemical process by converting the inputs into heat, carbon dioxide and ammonium. Ammonium is further converted by bacteria into plant-nourishing nitrites and nitrates through the process of nitrification.

The quickest and best way to know if you have enough spores is to plant then take a sample of the roots and have it tested for mycorrhizal colonization. No matter how many spores you add, they must colonize roots to be successful. Low to no colonization rates can occur if spores are not within close range of roots when they germinate. If they are not in close proximity to roots, they will die. If your soil is in good health, the mycorrhizal colonization process happens naturally. If you get the fungal and bacteria counts in balance and have good numbers of protozoa, mycorrhizal colonization will take place without any product inputs.
For row crops, vegetables, grass, most berries, shrubs and deciduous trees, vesicular-arbuscular mycorrhizal fungi (VAM) are the fungi of choice, while conifers and some late-successional deciduous trees require ectomycorrhizal fungi. Ericaceous plants, such as blueberries and rhododendrons, need Ericoid mycorrhizae. Earthfort tests for all three forms of mycorrhizal colonization.

Soil Testing

By knowing the current soil biology you are able to make adjustments that are more suitable for the desired crop, which will maximize crop production. Ongoing monitoring ensures optimal conditions throughout the growing season and leads to reduced dependency on fertilizers, pesticides, herbicides and fungicides which is more environmentally friendly and saves production costs. When using less traditional fertilizers you lessen the amount of salt in the soil which in turn requires less water consumption. In addition, good biology lessens soil compaction creating room for deeper root systems. Read More Here:
Earthfort specializes in soil biology; we believe if you can measure it, you can manage it. We have been measuring biology since the laboratory opened in 1996. We use proven methods of direct count microscopy which are referenced under our assay descriptions. Our Essential test assesses the moisture level (in soils and composts), total and active bacteria, total and active fungi, presence of aerobic protozoa; we can also test for nematodes (identified to Genus), E. coli, mycorrhizal colonization, and nitrogen cycling potential. see our testing order form for more details. After testing is completed, Earthfort provides a telephone report interpretation for those customers new to interpreting data. If requested, we are able to provide remediation consulting for those who want assistance on the practical application of soil amendments (fees may apply.)
No. We do not identify individual species of micro-organisms. We can test for colony forming units of Escherichia coli (E. coli) in soils, composts, and liquid amendments such as compost tea. We also can identify nematodes to Genus, only.
Please see our Sampling Instructions for instructions on sampling soil or solid (such as compost) and liquid (such as compost tea) amendments.

Call our office 541-257-2612 (or email info@earthfort.com) to request an official USDA PPQ Form 599 customs permit for sample shipping purposes prior to taking samples. Failing to follow USDA requirements for packaging and shipping of samples can result in delays in samples arriving at our lab and substantial fines up to $300,000 US dollars.


For our instructions page on packaging soil or compost for shipment within the continental United States,Alaska and Hawaii click here.
For our instructions page on packaging liquid (such as compost tea) amendments for shipment within the continental United States, Alaska and Hawaii Click here


For instructions on packaging soils, composts and liquid amendments for shipment from outside the United States, Click here You MUST request an official USDA PPQ Form 599 customs permit from Earthfort for your package before you ship your samples to us, and pay for shipping from your location to the USDA in San Francisco, California as well as shipping from San Francisco, California to our lab in Corvallis, Oregon. Please call our office 541-257-2612 or email us at info@earthfort.com for more information. Failing to follow USDA requirements for packaging and shipping of samples can result in delays in samples arriving at our lab and substantial fines up to $300,000 US dollars. Please call our office at 541-257-2612 if you have any questions about shipping samples to us internationally.

After taking your soil or amendment sample, (see instructions above) fill out our Testing Order Form. Plan to ship the samples the same day you gathered them, if possible. If you must store samples until the next day, keep them refrigerated. Do not freeze your samples, as the freezing and thawing will kill many of the microbes.
Ship your soil and compost samples so they will arrive within 3-4 days at our lab. Compost teas should be shipped by next day air to our location. Send sample to: Earthfort 635 SW Western Blvd Corvallis, OR 97333.

IMPORTANT NOTE TO INTERNATIONAL CLIENTS: Complete our foreign testing order form. Also, you MUST request an official USDA PPQ Form 599 customs permit from Earthfort for your package before you ship your samples to us, and pay for shipping from your location to the USDA in San Francisco, California as well as shipping from San Francisco, California to our lab in Corvallis, Oregon. Please call our office 541-257-2612 or email us at info@earthfort.com for more information. Failing to follow USDA requirements for packaging and shipping of samples can result in delays in samples arriving at our lab and fines up to $300,000 US dollars. Please call our office at 541-257-2612 if you have any question.

There are two times you do not want to pull a soil sample for biological testing: when the ground is frozen or water logged. Other than that, anytime will provide a good profile of the soil relative to the target crop.


Absolutely! Our products are certified organic through the Washington State Department of Agriculture (WSDA) as part of the National Organics Program (NOP) of the United States Department of Agriculture (USDA). It is advised to consult with your state’s own certifying agency prior to use as each state and country has slightly different rules and requirements. We can work directly with certifying agencies in your area to meet the required standards, contact us at 541-257-2612.
We work with conventional growers around the world, these products can enhance the system to allow for a more sustainable and efficient system. It is advised to contact us for best practices of integration; also, if you already have crop advisors and agronomists, we work directly with them to create a customized solution based on your needs.
These products were designed to be applied through any method that water can be applied; spray rigs, irrigation, overhead, drip-line, fertigation and aerial. Any type of pump can be utilized. Please note that these are natural products with some particulate matter; use 40 mesh (400 microns) or larger as finer meshes may clog. It is not recommended to utilize equipment that has been used for fungicide or pesticide applications as these products can kill or damage the beneficial organisms and substances our products contain. Also, compatibility testing is advised when tank mixing with other soil amendments and fertilizers. See our suggested general application rates here.


Each spray rig is unique, so you will need to calibrate your equipment to figure out how much water to use as a carrier for our products over a given area of land. Here is a workbook we compiled to help you do this: SprayerCalibration eGuide 2015.
Yes! Typically these products will enhance the biological processes in all operations that grow plants. For more specific use details please contact us to determine best approaches in your situation. General application is 32oz ProVide and 16oz ReVive in 50 gal resivor.
Compost tea is another tool to add biology to your soil; both of our products can complement and enhance a tea program. Soil ReVive is an excellent food source for tea production. Contact us for more details, recipes and consulting on the integration of Earthfort products into your regimen. General appliction if pre-treating your compost is to use 2oz ReVive with each pound of compost used. (if you use 5lb compost you need 10oz ReVive) You will use another 2oz per pound of compost in the water when you begin brewing.
These products can enhance and feed the biology in compost, whether as a part of the composting process or as a post composting enhancement they can assist in adjusting the biological balance. We offer consulting services to composters, contact us for more information.
Yes, in many cases we are able to send these products to international users. Please contact us for details as each country has different regulations regarding the importation and use of these products.

How To?

  • Wood chips, a couple of yards work well, alder, maple or some other non-aromatic wood.
  • Organic steel cut oats, about 50 pounds.
  • Source of starter biology, either a good quality compost tea (about 5 gallons) or Soil ProVide (one gallon).
  • Cardboard, non-waxy, with minimal printing, enough to cover the whole finished pile.

Create a 3-4 inch layer of wood chips apply the oats over the layer, spray it with the liquid, and then repeat the process until the wood chips are used up. Then cover the whole pile with the cardboard, it may be useful to put something over the cardboard to keep it from blowing away. Let the whole thing sit for 6-9 months, ideally on soil. After 6-9 months passes, mix the whole pile together and let sit for another 2-3 weeks, then take a sample and send it into our lab. (Note: This is just one recipe for making quality compost, many other base materials are possible).

Increasing diversity of soil organisms aid in the reduction of pest pressure.

Pest infestation and plant disease result from a lack of competition against plant predatory organisms. The rich biodiversity of healthy soil systems prevents the outbreak of over population of any one microbial species. Without protective ecology to balance the food web, plants are more vulnerable to antagonists and pathogens unchecked by competition from beneficial organisms. Determining the vitality of the organisms in your soil is the first step in supporting the diversity that will protect your plants.

Soil biology can increase a field’s water holding capacity by adjusting the chemistry and physical properties of a soil. As the organisms consume and excrete organic matter, they produce the substances that glue soil particles together, stabilizing soil aggregates and improving texture. This process creates a diversity of small pore spaces in the soil that hold water by the molecular forces of adhesion. Building soil biology to increase water holding capacity saves money on irrigation, prevents leaching of nutrients, and makes your soil more tolerant to drought.
Bacteria and fungi are the primary decomposers that break down dead plant matter and compost. Larger organisms, including protozoa and nematodes, eat the primary decomposers and excrete excess nutrients in a form plants can absorb. Most soils disturbed by over tilling and pesticides are highly bacterial and lack the protozoa and nematodes required to complete the nutrient cycle.

When you understand what biology is active and living in your soil, you can improve fertility by adjusting practices which support the organisms needed to balance your food web and deliver nutrients to the plants. Testing your soil biology will help you understand how nutrients become available to plants through the different communities of microorganisms that make up your food web.


Humic acid is the dark, stable component of fully decomposed organic matter. Microorganisms excrete small molecules from digested organic matter that attract each other and reform into large, highly complex supramolecules with chaotic structures that are very resistant to further decomposition. The molecular structure of humic acid is shaped by many folds and branches that create increased surface area with both positive and negative charges to hold all different kinds of nutrients and other ions in the soil solution. The complexity of the humic acid molecule also aerates clayey soils by separating clay particles with substances of lower density, holds excess water in micropores created by its high amount of surface area, and chelates heavy metals to release phosphorous and other nutrients tied up in insoluble molecular forms. Humic acid is the end product of living cells after decomposition. There is a very low concentration of humic acid in regular soils, especially low in agricultural soils with depleted organic matter content. There are higher concentrations of humic acid in finished compost. The most potent source of humic acid is from ancient deposits of slowly decomposed organic matter preserved from ancient wetlands eg. Alaskan humus. A good humic acid will be cold water processed as a low acid extraction. It will contain humic acid, fulvic acid, ulmic acid and trace elements.
Fish hydrolysate, in its simplest form, is ground up fish carcasses. After the usable portions are removed for human consumption, the remaining fish body, which means the guts, bones, cartilage, scales, meat, etc., is put into water and ground up. Some fish hydrolysate is ground more finely than others so more bone material is able to remain suspended. Enzymes may also be used to solubilize bones, scale and meat. If the larger chunks of bone and scales are screened out, calcium or protein, or mineral content may be lacking in the finished product form. Some fish hydrolysates have been made into a dried product, but most of the oil is left behind in this process, which means a great deal of the functional food component would be lacking.
Comparison with fish emulsion:
If fish hydrolysate is heated, the oils and certain proteins can be more easily removed to be sold in purified forms. The complex protein, carbohydrate and fats in the fish material are denatured, which means they are broken down into less complex foods. Over-heating can result in destruction of the material as a food to grow beneficial organisms. Once the oils are removed and proteins denatured and simplified by the heating process, this material is called a fish emulsion. The hydrolysate process has substantially lower capital and production costs compared to fish emulsion production.

Compost Tea

Compost tea is an aerated solution that is teaming with billions of beneficial microorganisms that can be applied directly to the leaf surface of a plant as a foliar spray or used as a soil drench to improve root systems. It is made by extracting and replicating the beneficial biology and diversity in compost into a liquid form. Compost tea works by putting the aerobic beneficial biological diversity that your plant needs onto the leaf surface of the plant or the soil. Compost tea should be used within 4 hours once the aeration has stopped. You can apply compost tea every two weeks to your garden.
Use a very small amount of organic corn oil.
Your D.O. meter should read between 7 and 10 parts per million; this measurement is taken while the tea is brewing. The tea should not fall lower than 7 parts per million dissolved oxygen.
Injection of the tea into an irrigation system is a very common practice and can be quite successful. Diaphragm pumps are the preferred type of pump as they tend to minimize damage to the biology. We have worked with tea pressurized as high as 300psi. The important consideration is  the impact pressure after the tea leaves the system.  Also, how many right angles or sharp surfaces does the tea have to travel over before leaving the system. Minimizing damage to the microorganisms by allowing adequate smooth travel through a given space before impact will help. Typically, it is assumed that once the tea exits the emitters the actual pressure drops dramatically.
Typically, to prevent foliar diseases apply 5 gallons of tea per acre every two weeks, starting a couple weeks before bud break. Continue every two weeks until harvest. If disease is observed, spray immediately on to affected areas, drenching the area. This results in protection of the leaf surface by beneficial organisms consuming or out-competing the disease.
Tea generally will remain aerobic for 6 to 8 hours. After 8 hours, aerobic activity falls rapidly due to lack of oxygen.