On Compost Tea and Liquid Biological Amendments

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

“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)

“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.