Q: What is the difference between and Actively Aerated Compost Tea and a Compost Tea Extract?
A: GEOTEA Liquid Biological Amendment (Extract) is an extract made from compost and water. While Active Compost Tea has a very short “shelf-life”, Liquid Biological Amendment (LBA) can remain viable for up to two months or more. This is because high quality finished and mature compost contains a vast diversity of microorganisms that have gone into different states of dormancy, or suspended animation.
The different kinds of microbes were very active during the actual composting process, but when a compost pile stops heating up and begins to look like “good black dirt”, or soil, this an indication that the microorganisms have run out of readily available food resources. With nothing more to eat, they go to “sleep”.
If a person makes a compost tea with just water and compost, it is considered an “Extract”, “Dormant Tea” or “Liquid Biological Amendment”. In the GEOTEA Machine, nearly all of the microorganisms in compost are extracted (dislodged) from the actual compost particles in one to two hours, due to the vigorous action of the patented “Submerged Extractor Dome”. Though the organisms are extracted into the liquid, because there are no new food resources, they remain relatively dormant, thus requiring very little oxygen. This is the reason for the ability to be stored for prolonged periods.
When food resources are added such as GEOTEA Complete, or liquid fish, molasses, kelp, etc., the microorganisms sense this new presence of nutrition and begin to “wake up”, grow and reproduce. With this new availability of food, the microbiological communities become very active and consume a large volume of oxygen as they vigorously grow and multiply, thus the need for a continual supply of oxygen until they are applied to plants or soil. If starved or limited of this vital oxygen supply, the compost tea quickly becomes anaerobic and conditions will favor the growth of pathogenic organisms instead of the beneficial microorganisms desired. This is the reason why an Active Compost Tea has a very short “shelf-life” (4 to 8 hours) once removed from an active oxygen supply.
Because the microbes in an Active Compost Tea are in the process of growing, multiplying and performing their metabolic activities, they can produce a lot of bio-film, or “slimes and glues”. This makes an Active Tea ideal for application to plant and leaf surfaces (foliar spray) because they have the ability to adhere well. When applications are directed onto soil or low lying plants (turf, pasture, etc.), an Extract might be preferred as the organisms will wake up and grow as food resources and environmental conditions allow. Often times, Dormant Tea or Extract is applied along with a food resource to help encourage the microbes to become active and multiply immediately as they hit the soil. Plants devote a lot of energy to produce exudates from their leaves and roots of which are largely comprised of microbial food resources.