The Biologic Method

The Biologic Method

We believe that soil is our most precious resource. Given the critical state of our world’s topsoil, it is vital to develop cultivation methods that effectively address the needs of human and soil life alike, producing clean air, water and crops for all inhabitants. Under the influence of chemical technology, agriculture and landscape management have achieved unprecedented success, though often with high costs and dire consequences. To create a truly balanced system, we looked to nature’s most successful ecosystems for our answers.

Soil Microbes: Nature's Invisible Worforce

Do you ever marvel at how a coastal California Redwood tree can grow to be over 30 stories tall without being fertilized? Or do you wonder how a wild fig tree can produce hundreds of pounds of fruit year after year, without the use of pesticides?

The Biologic Method

It is the diversity and mass of beneficial soil organisms that make such extraordinary growth possible. In Myceliated wood chip nature, you can find many examples, such as an old growth forest, where biomass production exceeds that of any cultivated system.

The Symbiotic Relationship Between Plants and Beneficial Soil Microorganisms

Healthy soil is a lively place! A single teaspoonful of good soil hosts billions of beneficial microbes. When all groups of microorganisms (bacteria, fungi, protozoa, and nematodes) are present in large population and diversity — both in the soil and on foliage — plants thrive and develop a strong resistance to pests and disease. These organisms perform functions critical to plant health in exchange for foods provided by each plant known as “exudates” (carbohydrates, simple sugars, and proteins).

On average, one third of a given plant’s energy from photosynthesis is used to produce exudates. These “foods” are then exchanged with soil microbes in return for benefits such as mineral chelation and protection from pathogens. This mutually beneficial relationship resembles a “biologic marketplace” where plants and microbes both prosper.

The BioLogic Method™

The BioLogic Method™ goes beyond other growing methods by creating truly regenerative systems modeled after nature’s productivity. From backyards to “big ag,” the BioLogic Method™ produces high-yield results (with minimal use of inputs) and eliminates the need for synthetic products. The BioLogic grower understands that beneficial soil microorganisms function as an elite, microscopic workforce that caters to your plants’ every need — from nutrient uptake to disease suppression. Results include better farm profits, higher food nutrition in crops, and improved soil conditions for future generations. The BioLogic Method™ is taught through our workshops, consulting, and educational materials.

Optimize Plant Growth: Beneficial Soil Microbes and the BioLogic Method™

Soil microorganisms perform the following functions vital to plant growth:

  • Build and maintain soil structure 
  • Protect plants from foliar and root diseases 
  • Convert macro- and micro-nutrients contained in the soil into plant available forms 
  • Fix nitrogen from the atmosphere and make it available for plant uptake 
  • Increase root growth and vigor 
  • Build water-holding capacity in the soil 

Understanding how soil microorganisms grow and interact with plants is the foundation of the BioLogic Method™. One can then apply this “natural technology” to any planting system to achieve maximum results.

Unintended Consequences of Conventional Agriculture

Many agricultural practices, including: long-term use of synthetic chemicals, frequent tillage, and soil compaction, have had a devastating “antibiotic” effect on soil microbial populations.

This loss of microbial life ultimately degrades soil quality and results in unhealthy plants requiring intensive cultivation in order to produce viable crops. Soil erosion and silting of local waterways is inevitable. In any ecosystem, be it an intensive greenhouse operation or a cattle pasturing system, BIODIVERSITY of organisms from bacteria to fungi to mammals is the key to creating regenerative and sustainable systems.


BioLogic Systems has conducted extensive research in order to better understand what specific methods and materials actually produce the exceptional benefits that are touted by compost tea enthusiasts. Thorough testing of our products and organic materials has revealed many factors that influence the process of making effective compost teas. The BioLogic Method™ relies on high-quality inoculants including humus, composts, and mycorrhizal products. In order to stimulate microbial reproduction, “food stocks” such as kelp and fish hydrolysate are added. The liquid form of these ingredients can be easily applied to plants using root drenches and foliar sprays. Application quantity and timing vary depending on the crop and climate. Many philosophies exist in regards to how to make and use compost tea. BioLogic Systems has adopted the following terms “Compost Extract” and “Active Aerobic Compost Extract (AACE)” to describe the specific processes we recommend.

Compost Extract vs. Active Aerobic Compost Extract

"Compost Extract” is made by releasing the clinging microorganisms and nutrients from high-quality compost into a container filled with water. Making compost extract is a very easy and efficient process; a batch of compost extract can be made in about five minutes. First the compost is placed into a mesh bag. Then a mechanical or manual motion pushes the microbes and nutrients through the mesh into the water. Next, microbial foods (fish hydrolysate, kelp, etc.) are added to the water. Once the extract is applied to the soil, the microbes consume the added foods and reproduce. “Active Aerobic Compost Extract” (AACE) is used for foliar applications. Making AACE involves an additional step, often called “brewing,” that requires a “tea brewer.”

The compost extract (described above) is aerated for one hour or more allowing for aerobic microbial reproduction in the brewer. During the aerating (brewing) period, the microorganisms emerge from their dormant state and reproduce. As the microbes grow, they produce a slime layer (a “bio-glue”) around themselves that increases their ability to adhere to leaf surfaces when sprayed. AACE takes 18-72 hours to brew depending on the ambient air temperature.

Aerobic vs. Anaerobic Compost Teas

Every skilled grower knows the importance of oxygen penetration into the soil or growing medium. Almost all beneficial soil organisms prefer aerobic (oxygen rich) conditions. Anaerobic (low oxygen) organisms do exist in healthy soils, although in very small populations. Many anaerobes will produce toxic metabolic by-products such as alcohol and phenols. The easiest indicator of anaerobic microbial growth in a compost tea is the emergence of a foul smell.

The potential for brewing anaerobic or facultative (partially anaerobic) compost tea makes compost extract a more practical method for small-scale growers. BioLogic Systems employs procedures to ensure aerobic conditions are maintained at all times in our brewer designs.

Inoculum-Grade Compost is Essential

The quality of all compost extracts results from the grade of compost used. Compost (worm, thermal, static, or humus) quality is a function of the diversity and biomass of beneficial micrograms (nematodes, protozoa, fungi and bacteria) per gram found in the finished compost. Inoculum-grade composts contain billions of microorganisms including thousands of different species per gram.

Testing of compost products is essential to assess compost biology. As composting methods and materials vary widely, microscope assessment is vital in determining microbial diversity and biomass.

Desired Microbiology in Compost

  • 15+ µg active bacteria/gram
  • 150+ µg total bacteria/gram
  • 10+ µg active fungi/gram
  • 150+ µg total fungal biomass/gram
  • 50,000 or more protozoa/gram
  • 20 to 100 BENEFICIAL nematodes/gram
  • Fungal hyphal diameters 2.5 micrometers or greater

(values express micrograms () or individuals per gram of compost)


Most compost tea brewers use “air-stones” to produce small bubbles in the solution. The porous nature of an air-stone is inherently problematic. They are difficult to clean and often become a host site for the accumulation of anaerobic “bio-film.” BioBrewers™ utilize “Big Bubble Aeration,” the action of large bubbles provides excellent dissolved oxygen maintenance. By creating specific wave patterns that break the water surface tension, “Big Bubble Aeration” mixes the fluid completely, keeping valuable materials from settling on the bottom of the brewer and becoming anaerobic.