Compost tea is a liquid extract from mature, cured compost. It is not to be confused with leachate, or liquids which may run off a compost pile during heavy rains. Compost tea is made by fermenting cured compost in a bucket with water for 24 hours to 14 days. The solids are strained from the liquid and the resulting liquid is compost tea. Compost tea offers many benefits to gardens and crops but must be made with care to ensure its nutritional value. (See References 1)
How It Works
The types of microorganisms in compost tea are different from those in the original compost. This is because some microorganisms prefer to live attached to solid organic matter and will not thrive in liquid. Some of the beneficial microorganisms in compost tea include aerobic and anaerobic bacteria, fungi, actinomycetes, pseudomonads and nitrogen-fixing bacteria. Apply compost teas directly to the soil or to the leaves of the plant. Adding them to the soil allows roots to absorb the nutrients while also improving the soil nutrition. Applying compost tea directly to the plant allows microorganisms and nutrients to assist in disease suppression and nutrient availability. (See References 1)
Compost tea affects plants more quickly than compost mixed with soil. It can help plants suppress disease by inoculating plants with beneficial organisms such as bacteria, yeasts or fungi (see References 2). Compost teas reduce the need for fertilizers, improve plant growth and uptake of nutrients, increase a plant's nutritional quality and lower the costs of production. (See References 1)
The drawbacks of compost tea are mostly related to quality issues. Compost tea made from compost that is nutrient deficient, uncured or lacking in microorganisms will yield poor quality tea that can actually harm plants rather than enhance them. Compost with high levels of salt, anaerobic microorganisms or pathogens will also produce low-quality tea. (See References 1)
Aeration can speed up the production time of compost tea. You can further enhance the nutrient value of your tea by brewing it with a microbial nutrient source such as molasses, kelp or fish byproducts. Compost tea should be applied to soil or plants promptly after brewing; otherwise, when the microorganisms use up available oxygen in the tea, it turns anaerobic and kills the beneficial bacteria. (See References 2)
Hailing from Austin, Texas, Beth Berry has been writing since 1995 about sustainable farming, fiber arts and parenting. She brings expertise in organic gardening, landscape design and domestic arts to her writing. Berry holds a Bachelor of Science in environmental science from Abilene Christian University and is a master seamstress.