Compost Extract & Tea

What is the difference between USING compost extract and tea?

Compost extract is used for soil drenches and can replace fertilizer and other chemical inputs as a way to inoculate the land with beneficial microbes to help your plant grow. Extract will help boost the ‘immune system’ of plants roots by covering the surfaces with beneficial microbes.

Compost tea is used for above ground applications and coating seeds. Compost tea sticks to surfaces of your plant because the bacterial and fungal glues. For orchards, tree farms, or any above ground issues in fertility compost tea is the best tool to increase your plants health. Tea will help boost the ‘immune system’ of your plants above ground by covering the surfaces with beneficial microbes.

What is the difference between making compost extract and tea?

Compost extract is made by extracting the organisms from your compost through pressure. For smaller operations this can be done in a 5 gallon bucket with a 400 micron mesh bag, and massaging a small amount of compost in ambient temperature water.
For larger projects a conical extractor/brewer with an air pump is recommended. Suspending your compost in a 400 micron mesh bag for at least 10 minutes; letting the air circulate through your compost & extracting the biology. For very large operations an auger can be used to move the compost upward and water sprayed on at 80 PSI to extract the microbes.

Compost tea is made through a brewer/extractor in the same process of aeration but for longer periods (24 hours) with foods added to keep the beneficial microbes alive (a foods lists can be found at the bottom of this page. )

When to Apply Compost extract or tea?

Make the extract or tea right before applying to your soil or plant. This can be done at any time in the day since the water attenuates UV rays. Bacterial and fungal glues also reduce UV exposure.

Multiple applications may be necessary depending on the situation, if it is starting as bare ground and a monoculture is being grown, inputs could be done with a tea covering the seed coat, an extract at the time of seeding, after first true leaf, and throughout the season if necessary. However if the ground is covered in a low growing perennial understory ground cover this will help keep the microbes fed with exudates from photosynthesis (sugar, carbs, and a little bit of protein.)

How much compost extract should I apply?

The general rule of thumb is 1 gallon per acre, however this is dependent on the quality of your compost. If the compost is not biologically complete you will need to increase your input.

How much compost tea should I apply?

Cover every surface or the plant or seed, this means underneath the leaves, trunk, stems, every part of the plant.

Can I Apply too much extract or tea?

Unlike chemical fertilizers which can have adverse effects if not perfectly applied like burning your plant if too much is applied, or washing away in the rain, beneficial soil microbes will not harm your land regardless of the concentration.

If too little extract is applied the little bit of microbes (like all living things) will reproduce. While it will be a slower effect, and may even take another growing cycle, those microbes will eventually populate your soil and provide the benefits of soil biology.

If too much extract is applied the positive effects will be apparent in that growing season, and especially if the ground is always covered plants, the organisms will spread and your neighbors might even receive their benefits.

If too much tea is applied it will drip off the plant surfaces and also benefit your soil surface.

How Should I Store my compost before making it into extract or tea

The living organisms in compost, like humans, prefer to be in 50º-80º F, extreme temps can change the microbial environment. Keep the compost out of direct sunlight, UV causes damage to micro-life. Store Indoors at ambient temperature.

What about my water?

A water test should be done if using well water to be aware of heavy metals chemicals and pollutants present. If you are using water that has been treated by a municipality chlorine and chloramine (among other things) will be present in your water, this will kill beneficial microbes and reduce effectiveness. To complex and bind these compounds humic acid should be applied, very little is needed, just enough to see visible color change (generally 1 drop per gallon)

The water should be at an ambient temperature so the microbes in your compost do not die from thermophilic shock. Whatever the temperature you are growing, that is the necessary temperature of your water (if growing in a greenhouse, water should be at that same greenhouse temperature.)

equipment Maintenance?

After compost extract or tea is made and applied your equipment should be cleaned immediately with high pressure water. This can be as simple as a hose with your thumb over it or a pressure washer. Be sure to clean the lip of the brewer/extractor and the valve area as these areas are spots where a biofilm will build up.

Any 90 degree angles in your pipes from the brewer/extractor to your sprayer will also be areas of biofilm buildup that needs extra attention when cleaning. These harsh angles are also spots where you will reduce your compost liquid health and damage or kill organisms from the pressure of hitting that wall; if possible retrofit and remove those angles (think of a waterslide, you wouldn’t want to hit a 90 degree angle near the bottom either.)

How do I make Humic Acid?

Take 1 cup of your nice rich dark brown (looks like 70% cocoa chocolate color) compost.  Place it in cheese cloth in a funnel or sieve (colander) on top of a clean container (a jar for example), arranged such that you gently pour water onto the compost in the cheese cloth, and let the water PASSIVELY move through the compost, and drain into the clean container.  The dark rich chocolate color is produced by humic acids, which should stay in suspension as they are soluble.  If the dark color settles to the bottom of the container after a half hour or more, then that's particulate humus, not humic acids.  The humic acids at the concentration that you see the 70% cocoa chocolate color is great enough to add 1 drop of the humic acids into a gallon of water and neutralize chlorine, chloramine and other contaminants.   You expect to see a slight tan color remain in the water, if the humic acids have neutralized all the chlorine and chloramine, etc.  If you don't see a slight brown or tan color remain, add a second drop. 

While other organic acids can also be used to neutralize pollutants in your water, humic acid is the only one with a visible color change, which is why Dr. Elaine Ingham and many other soil scientist recommend it.