A liquid made by steeping compost in water to extract soluble nutrients and microbes. Aerated compost tea (ACT) uses active aeration; non-aerated extracts are simpler but microbially different.

Does compost tea reliably boost plant growth or disease suppression?

Results are mixed. Outcomes depend on compost quality, handling, and application context. Many growers see consistent benefits from applying finished compost, mulches, and cover crops directly.

Are there safety concerns with compost tea?

Yes—unsanitary materials or handling can introduce human pathogens. Use only well-finished, plant-based composts, clean equipment, potable water, and avoid foliar applications to ready-to-eat crops near harvest.

What simple alternatives support soil biology?

Top-dressing with finished compost, maintaining living mulches or cover crops, and minimizing soil disturbance reliably increase beneficial microbial activity with lower risk.

When might a liquid compost extract be useful?

Some growers apply filtered extracts to drip or as a light soil drench for establishing transplants. Keep applications to soil (not edible leaves), and prioritize sanitation and source quality.

How does this fit into Crop Circle Farms systems?

Core practices—finished compost, cover crops, diverse rotations, and drip irrigation—build soil biology. Liquid extracts, if used, are supplemental and applied with sanitation and crop safety in mind.

Compost Tea | Aerated vs. Non-Aerated, Safety, Efficacy & Use

Compost Tea – Nutrient-Rich Fertilizer You Can Make Yourself

Compost tea is a liquid extract made by steeping finished compost in water to dissolve soluble nutrients and mobilize microorganisms. Growers use it primarily as a soil drench to supplement biological activity rather than as a replacement for compost or organic matter.

Results from compost tea vary widely and depend on compost quality, sanitation, brewing method, and application timing. While aerated and non-aerated teas differ biologically, neither consistently replaces the benefits of applying finished compost, mulches, and cover crops directly to soil.

This guide explains how compost tea works, the differences between aerated and non-aerated methods, safety considerations, and lower-risk alternatives for building soil health in gardens and farms.

How Plants Benefit from Oxygenated and Non-Oxygenated Compost Tea

Two variations of compost tea exist: oxygenated and non-oxygenated. Oxygenated compost tea involves introducing air to the water while the compost steeps, fostering the proliferation of advantageous aerobic microbes like bacteria and fungi that assist in decomposing organic substances and converting them into plant-accessible nutrients. Non-oxygenated compost tea, on the contrary, is created by allowing the compost to steep in water without any added air. While still nutrient-dense, it may not possess as many beneficial microbes.

Microorganisms in compost tea are vital in fostering soil health and plant growth. Bacteria contained within the soil decompose organic substances and free up nutrients. Helpful fungi like mycorrhizae and trichoderma aid in enhancing soil texture and boosting nutrient absorption by plants.

Nutrient Cycling: an essential process for soil health

Compost tea plays a pivotal role in nutrient cycling, an essential process for soil health. When organic substances are added to the soil, microbes break them down, releasing nitrogen, phosphorus, and potassium. These nutrients are then absorbed by plants, which add organic matter back to the soil upon dying and decomposing. This nutrient intake and release cycle is vital for maintaining fertile soil and promoting plant growth.

The Soil Food Web: A Microcosm of Life Beneath Our Feet

A complex network of microbes, fungi, and other living organisms inhabiting the soil, are indispensable to soil health and play a critical role in nutrient cycling. The beneficial microbes contained in compost tea help build this Soil Food Web living right beneath our feet.

Making Oxygenated Compost Tea

Creating oxygenated compost tea involves some basic ingredients including compost, water, and a brewing container. Here's a detailed guide on preparing oxygenated compost tea:

Fill a mesh bag or stocking with compost, leaving enough space for it to expand.
Fill a sizable container (a 5-gallon plastic bucket from Home Depot is perfect) with water.
Submerge the bag of compost into the water.
Add an air stone and air pump to the container, enabling air circulation through the compost tea.
Allow the compost tea to brew for 24-48 hours, stirring occasionally.
After brewing, remove the compost bag and strain the liquid using a fine mesh strainer.
Dilute the compost tea with water at a 1:10 ratio (one part compost tea to ten parts water).
Use the compost tea to water your plants, ensuring both the leaves and soil are covered.

Non-Oxygenated Compost Tea

The ingredients for non-oxygenated compost tea are simple and easily accessible.

Ingredients:

1. High-quality compost: You can use homemade or purchased compost. Ensure it is well-aged and pathogen-free.
2. Water: Filtered or dechlorinated water is preferable.

Optional ingredients:

1. Molasses: It serves as a natural carbohydrate source, feeding the microorganisms in the tea.
2. Kelp meal: Kelp meal supplies micronutrients and trace elements beneficial to plant growth.
3. Worm castings: These are rich in beneficial microorganisms and nutrients that can boost the tea's effectiveness.
4. Epsom salt: It provides magnesium, an essential nutrient for plant growth.

Step-by-Step Method for Making Non-Oxygenated Compost Tea

1. Fill a container with water. A 5-gallon bucket is liftable when filled three-quarters from the top.
2. Add compost to the container at a compost to water ratio of about 1:5 or 1:10. (to achieve this, you should add 1-2 gallons of compost to the water filled bucket).
3. If using, add optional ingredients like molasses, kelp meal, worm castings, and Epsom salt. Use about 1-2 tablespoons per gallon of water.
4. Stir the mixture thoroughly to ensure the compost is fully submerged.
5. Cover the container with a lid or cloth to keep pests out.
6. The mixture should sit for 3-5 days and be stirred occasionally to aerate and steep. Leaving the bucket in the hot sun will cook more of the mixture making the tea more potent.
7. After 3-5 days, strain the mixture to remove any remaining solids.
8. To soften the mixture for delicate plant applications, dilute the tea with water at a ratio of about 1:10 or 1:20. For instance, dilute a 5 gallon with 10-20 gallons of water if you have 1 gallon of tea.
9. Once finished, strain out any large compost pieces and apply the liquid to your garden soil.

Compost tea is an excellent medium to improve soil health and support plant growth. Whether you opt for oxygenated or non-oxygenated compost tea, the beneficial microorganisms in the tea will contribute to improved soil structure, promote nutrient cycling, and enhance the soil food web's health.

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