Why Use Compost Tea?

Compost tea, or compost extract, is an economical way to deliver many of the benefits of high-quality compost efficiently and effectively. Compost tea is a water-based extraction of the soluble minerals, humic substances, and microbes from high-quality compost. A food source is also added to the compost tea to stimulate microbial activity and reproduction. High-quality compost tea is a source of diverse beneficial microbes which, along with microbial food sources, multiply numerous times on crop leaves and in the crop’s root zone. Compost tea is typically applied to the soil by a side dressing in the furrow or as a foliar spray. The diverse microbial profile in compost tea help the plant’s leaves absorb nutrients from the air, and as they find their way into the soil, they help the plant’s root system extract nutrients from the soil. As a liquid it is more economical to ship and easier to apply to the plants.

The Process Makes the Difference

The quality of any compost tea is dependent on the quality of the compost used. The method of production, however, also impacts the stability and effectiveness of the final tea product. The two most commonly used methods for producing compost tea are tea brewing and tea extraction. While both methods are effective in their own right, extraction provides distinct advantages that are worth noting.

Extraction Method:

The extraction system uses more high-quality compost, effectively extracting the soluble minerals, humus, and microbiology into a concentrated liquid. No food sources are added immediately, allowing the inactive microbes to remain inactive, thus conserving oxygen. Because the microbial population is not made active by adding food during the extraction process, the microbial diversity that exists in the compost is preserved. Activators are added to the compost tea just prior to application. The activators are specific food sources that “wake up” the microbial population causing the microbes to become active and begin rapid reproduction. The active microbes are immediately applied to the crop where they continue to multiply in a natural environment that favors preserving the original microbial diversity.

Brewing Method:

In the brewing method a food source is added at the beginning of the brewing process to encourage the microbes to multiply. The food source causes the microbes to become very active but it shortens the effective life of the compost tea. Being active is good when the microbes are applied to crop leaves; however they consume much more oxygen when they are active. The increased oxygen consumption rapidly depletes the oxygen available in the water, causing the microbial population in the compost tea to become dominated by anaerobic species in a short period of time. If the compost tea becomes anaerobic, its effectiveness is limited.

With the extraction method no food sources are added immediately, allowing the inactive microbes to remain inactive, thus conserving oxygen. This extends the useful life of the tea. The extraction method produces a product that is shelf-stable, and it offers the flexibility of activating for use as compost tea just pror to application.

Chemical-based fertilizer, pesticide, insecticide and herbicide can kill some part of the beneficial life that exists in soil. Compost teas, correctly made and applied, improve the life in the soil and on plant surfaces. Using compost and compost tea will increase the beneficial soil microorganisms and reduce disease-causing pest organisms. Compost tea feeds the microbes in the soil that make nutrients available for the plants.

Foliar or root applications of compost tea provide many benefits. These can include:

Disease suppression — humus compost has a healing effect on plants and a cleansing action on soils.
Increases plant yield
Porosity increased in the soil-has more air voids than typical soils.
Nutrient retention — magnetic charge from high CEC holds nutrients longer.
Compaction reduction — it makes soil spongy and enables it to spring back.
Helps reduce dependence on chemicals — promotes healthier plants.
Erosion reduced-disperses the force of raindrops.
Water retention increased — like a sponge holding water.