Does Compost Tea Work?

On this month’s installment of the testing garden assumptions series I am going to evaluate the two main claims made about compost teas.
Today’s first hypothesis is that AACT increases the number of bacteria through the brewing process however is not necessarily an organic fertilizer.
The second hypothesis is that Compost extractions are an organic fertilizer.
0:40 What is Compost Tea?
0:58 What is Actively Aerated Compost Tea?
1:16 What is a Compost Extraction
1:29 Why is Fertilizer Needed in the Garden?
1:39 Why are Bacteria Needed in the Garden?
3:54 Compost Tea Recipes
5:45 Nutrient Results
8:09 Bacteria Culturing Results
9:35 Summary of Results
10:03 Follow up Video on Compost Tea Product Claims
Check us out on Facebook:
/ albertaurbangarden
Related Videos:Is Epsom Salt useful in Organic Gardening?
• Is Epsom Salt Benefici...
Part 2 Is Compost Tea a Valuable Method in Organic Gardens? Testing Garden Assumptions Series Playlist:
• Testing Garden Assumpt...
Is Rainwater Safe to use in the Garden?
• Is the Rainwater Colle...
Lab Results:
20 - 20 - 20 Synthetic Fertilizer Dry and Wet
www.albertaurba...
Compost Tea Lab Results Including AACT, and Compost Extraction
www.albertaurba...
Supporting Material:
[1] Is Rain Water Safe to Use in the Garden?
• Is the Rainwater Colle...
[2] Kelp fertiliser and amendments in Organic Gardening
• Kelp Fertilizers and S...
[3] Dr. Linda Chalker-Scott’s resource paper on foliar application
puyallup.wsu.ed...
[4] Dr. Linda Chalker-Scott’s resource paper on Compost Tea’s Pesticide use
puyallup.wsu.ed...
[5] Dr. Linda Chalker-Scott’s resource papers
puyallup.wsu.ed...

[@patto2006]

Does anyone else find the comments discussion almost as interesting as the video itself? It really says a lot about your videos and your viewers. Keep up the great work Stephen.

[@AlbertaUrbanGarden]

Thank you my friend ! I really enjoy the comment section !!!

[@springrollwang4441]

+patto2006 It is, but what I don't understand is why does he get less views compare to other channels which just praise some products and didn't even test it. It's like viewers prefer to believe in something fantastic and don't want to try out if their belief is true. Bcs some channels suggest you to put as much rock dust as you can....and have more views but which application has negative impact on your garden overall.

[@AlbertaUrbanGarden]

Well my friend its likely to do with how long other channels have been making videos. I started in 2013 where as some have started as early as 2008. That is a lot of momentum for me to catch up on ;) I really do appreciate all of your views!

[@juguruteacher6204]

This is a highly underrated channel. I love all the experimenting you do. I often do my own but it's nice to see other peoples experiments to save time and share ideas. Thanks for these.

[@angef9687]

My Great Grandfather used to have us kids go out into the pasture and collect sunbaked cow patties which he would soak in pails of rain water and then after a few days he would then water the garden with it. He always had a bountiful garden

[@KevinModz65]

We did the same thing but made snack chips out of them. Didn’t taste too well but our skin was shiny 😵‍💫

[@paulmaxwell8851]

That can be risky. Broadleaf herbicides such as Grazon are used extensively in pastures and hayfields across North America. One of the active ingredients, Picloram, passes unchanged through grazing animals and ends up in the manure. If you unwittingly bring that home and use it in the garden it will destroy all non-grasses, and take five or more years to slowly disappear. Be careful!

[@ricko2301]

😂😂😂​@@KevinModz65

[@ugtitto2654]

Scientific testing aside, my compost tea experience was amazing. It does make plants healthy and strong to take all the nutrients they need from whatever soil they have in various parts of my garden. After I’ve introduced compost tea to my garden, I forgot about plant diseases. If I want to boost some blooms, I can always use a bit of a synthetic fertilizers, but only as a “dessert”, never as the “main course”. I avoid stressing my plants out with synthetic fertilizers. I opt for healthy root systems.

[@ShopperPlug]

Maybe he should do some tests to see if aerated "Compost Tea" is maybe better for controlling and preventing plant disease than microbial number counting.

[@asamiyashin444]

Yeah, I'm tired of "scientific" reductionism.

[@chevy6299]

Had a feeling the results would end up like this. You are the only one doing testing like this and I sure do appreciate it you efforts.

[@AlbertaUrbanGarden]

I am glad I can help. I just take the video where the evidence takes me! :)

[@Diseaseisreversible]

@@AlbertaUrbanGarden why did you stop making videos?:(

[@Ladybrite1]

Look up Dr. Elaine Ingham. Lots of microbial study there.

[@jasonharrold6686]

Interesting. I always use Compost Tea not as a "fertilizer" but to assist my plants in absorbing nutrients already present in the soil and to increase soil biology

[@timpage5021]

Exactly

[@rhyothemisprinceps1617]

That's my understanding of the purpose, also. There is a scientific review article on it - 'Rhizophagy Cycle: An Oxidative Process for Plants ...' by White et al., published in 2018 (so it post-dates this video, however, I think the concept was known before )

[@kicknadeadcat]

Compost tea feeds the soil and worms which feed your plants. And the best thing about it is that ill never overfeed so you can use it everyday. It's easy to make why not use it.

[@RobsAquaponics]

Nice one Stephen. Am a big fan of making up a tea as a way to spread compost around rather than brewing for increased benefits. Really interested in seeing if the commercial tea brews are as good as a basic home made one ;) Cheers mate.

[@AlbertaUrbanGarden]

Rob that is a good method to spread your compost and water based on todays results it likely is a slower process to release the nutrients which is fine if you have a healthy nutrient cycle like you do!

[@RobsAquaponics]

+Dennis T Menace All is good mate. My thoughts are that the home made would be just as good that's why I'm interested in seeing a test ;-)

[@AlbertaUrbanGarden]

intersting note and preview of this weeks episode worm castings made at home have more effective humic acid and plant growth hormone.

[@cs1lva53]

@@AlbertaUrbanGarden when we make compost tea we look to benefit from the micro organisms it yields. trying to use it as a fertilizer is way off base, you set up a Straw Dog, are you "Uninformed" about this?

[@ChrisCross2014]

This is the chanel I'll view if I want good solid, scienfiic results. Thanks for all your hard work.

[@AlbertaUrbanGarden]

+Kac P_man Thank you for the kind comment!

[@theswedishgardenamateur4271]

Thanks so much! Really appreciate your efford to try to bring some clarity regarding all tips that are around! I simply use compost on top as a mulch and then let my watering, rain and worms do the rest! This seems to work very nice! Simplicity is also a factor for me! Looking forward to your next video🌸

[@AlbertaUrbanGarden]

+The swedish garden amateur the science I have found to date certainly supports that simple method :)

[@kreeetin]

I have to agree!

[@robinettefamilyfarm3510]

Great results Stephen! I love that u have a lab close by to test all of these myths. I steered away from AACT a while back because I didn't see the benefit of it if I already use plenty of compost in my garden. I agree with Patrick, compost and mulch can provide all the nutrients and beneficial bacteria your plants need. I'm looking forward to your follow up video!

[@AlbertaUrbanGarden]

+DownToTheRoots the work I do with the lab sure has helped clarify things for myself as well ! Patrick is onto something. Less work and the same if not better results.

[@tombryant4518]

You need to brew it properly, and then test it properly. The brewer in this video was useless. You’ll see the results under a microscope, not in a Petri dish

[@RJ-rs6rf]

No reply from op🤔 Wonder where this guy works, Whats he have to gain by promoting chemical fertilizer? Publishing results for a brewed product that you dont actually brew? Hopefully people do the side by side tests for themselves with their soil in their climate zones with well documented Composting and brewing techniques shown to increase yield. As shown by large scale grow operations in Holland that use zero chemicals only tea. Rainwater has beneficial bacteria? Where does HE live cuz....🧐

[@RJ-rs6rf]

en.m.wikipedia.org/wiki/Regenerative_agriculture

[@daddykirbs]

My belief (not scientifically tested) is that it can help jump start good soil life when turning a degraded area into a garden. After that initial "boost", I think just compost and mulch would do the trick just fine. Even with that belief, I probably would just go with compost and mulch and let nature do it's thing. I appreciate you taking the time to consider these practices and challenging them in a scientific way. Put on your armor every time you take on one of these challenges! There are many people who will defend their methods quite aggressively! :) You are doing great work my friend.

[@AlbertaUrbanGarden]

+Blake “Daddykirbs” Kirby the more work I do on this subject the more I am in agreement mulch and compost left on its own will do the work better and more effectively. No need to fight nature. Some days my friend I wish I had Armour but that is the life of a man of science. one must not cower from opposition rather embrace it as an integral part of the work.

[@wiitele]

Your videos are very well done and super informative. I am sure a lot of people are not going to like these results as they live by the compost tea but proof is proof. Thanks for taking the time to do the experiment and sharing your findings.

[@AlbertaUrbanGarden]

+wiitele it is my pleasure and I am glad you enjoyed the video! Have you seen part two of this video?

[@Realdavidart]

Wouldn’t it be easier to just have two sets of plants. Feed one set the tea. And gauge the results? Rather than assume you or anyone else truly know the infinite number of bacterial interactions in plants or the beneficial effect of that bacteria in the food and humans who consume them.

[@blackbirdbeatle]

I mean, where do you think people have come up with all these aerator ideas? They research this exact thing (Compost tea) and how microorganisms work with plant health and soil at countless universities around the world. They've been doing this for many, many years. If you do it correctly, it works.

[@keyplayr61greenhousehydrop14]

I have tried compost tea, both foliar, and in the soil, and I could not see any difference! So I would say your tests are completely accurate, Stephen!

[@AlbertaUrbanGarden]

+Keyplayr61 Greenhouse Hydroponics And Gardens that is good to know. I think people testing methods out and making decisions based on their observations is fantastic !

[@wolfgangwunschel-b4p]

the passive broths (popular in biodynamics) require daily stir it ups for its short oxigenization instead of turning anaerobic.

[@meehan302]

I used compost tea last year and apart from the smell I did not notice any difference. Thanks Stephen for highlighting the subject and your analysis too. Will be interested to watch the replacement.

[@AlbertaUrbanGarden]

+Patrick Meehan I really like seeing gardeners use evidence they generate to make decisions !

[@BoKnowsAll-24]

Also the main purpose for compost tea isnt its fertilizing abilities but the billions of benificial microbes that will battle diseases on the plants and make them and your soil thrive!!!

[@davidjudd221]

Daniel Deringer, agreed, I've used compost tea for years, and never once thought of it as a fertilizer. I only use Alaska Fish fertilizer for the purpose of fertilizing. I do know one thing for sure, the tea works. Good day.

[@joseluizm.garcia998]

The number of the different species present in Compost is extremely lower than in Compost Extract. Period.

[@MrTimjwilson]

I would say that you have made a few errors in your statements and experiments. What you describe as a compost extract is actually a non-aerated compost tea, referred to as NCT in scientific research. Compost extract or Liquid Compost Extract (LCE) are both utilized for primarily microbial content and NOT nutrient content, although as you discovered there is some residual nutrient value. If my friend Jeff has stated this in the book you said you sourced then he just got it wrong. So you know LCE is a fast extract process. e.g. we do 50 gallons in 5 minutes and use 4 times the amount of compost used in CT. You are fixated on bacterial multiplication but that is only a portion of the microorganisms extracted and multiplied in aerated compost tea (ACT - the term AACT is 100% silly - google Microbe Organics) Depending upon your compost quality/activity and the quality of your bioreactor (CT maker) you should see increased levels of bacteria, archaea, flagellates and/or naked amoebae and fungal hyphae if present in your compost. You may see lots of youtube video data on the above mentioned resource. The general idea for nutrient cycling provided via compost tea is to extract & multiply a good ratio volume and diversity of bacteria/archaea and flagellates &/or naked amoebae (protozoa). This generally requires about 36 hours of running a quality design bioreactor (brewer) and providing adequate feedstock if needed (I agree that kelp is a poor option). As the protozoa feed on the bacteria/archaea they utilize only 10 to 60% of the nutrient value for their own sustenance. The other 40 to 90% is discharged in plant available (bio-available) ionic form. This is how a nutrient boost is provided to the roots of the plants. There are hypotheses about disease suppression utilizing CT but I'm not getting into that here. Testing: You have noted, accurately, that plate culture testing is not a good choice for this application. Probably the nutrient testing is not either but I don't think you mentioned the extraction process used by the lab. Many of these are inaccurate when researching sequestered nutrients. A better procedure would have direct microscopy and microbial count. Bioreactor; I've often stated there is no such thing as bad compost tea but it is easy to make it better. I would improve your brewer by using a pump outputting around 1 CFM (or use several small pumps). I would run air with diffuser into the extraction bag and consider running for 36 hours but 48 isn't terrible. Once agitation is improved you could use up to 0.5% molasses by volume. I would say that putting the compost directly into the water and stir with whathaveyou would produce superior results to what you have used. Keep on learning:)

[@thearkedcrown]

Is there a good review article on this?

[@aquienpuedainteresar4188]

That's a lot of info specifically for a some one who has never done this before...is there a video that show in practi6what you said here.

[@deitykush]

Sounds like you would be able to make a great video. Possibly mentioning everything you mentioned in this comment and everything he mentioned as to mention the pros and cons

[@ingoscarpatti3070]

Nice insights. And yes, a video would be terrific aswell. Please, consider making one

[@kenmosely540]

Watch elaine ingham microbiologist she's explains it the best

[@knitnpaint]

So very interesting. I was going to buy a pump and stone to try this method. YOU are so amazing in your approach to gardening. I look forward to your videos. I did make the tea with just the soaking from wormcastings. It looks like I might just as well just add the wormcastings to top layer of the soil and be done with it. Thanks for all the research. Can't wait for the next episode.

[@AlbertaUrbanGarden]

+knitnpaint Thank you my friend! I am glad you enjoy my videos! I really enjoy making them! You are likely right add the worm castings to the mulch and sit back and count the pennies you saved!

[@CosasdelJardin]

breath taking video!

[@AlbertaUrbanGarden]

+Cosas del Jardin Thank you. I let the evidence guide this one and as I was researching and writing it I was just as shocked.

[@CosasdelJardin]

***** it certainly is not good news for urban gardeners

[@AlbertaUrbanGarden]

+Cosas del Jardin Well it is good news. It saves a process that is not living up to its claims. There are other alternatives that will provide the benefits we are looking for with less effort. some of the claims about compost tea though have been exaggerated and that I can't fix.

[@CosasdelJardin]

***** Ok, Im going into winter. Ill be patient, I can wait until august for you to discover a better fertilizer hahahahahaha

[@foxvulpes8245]

What temperature where they at? I would also point out that as an individual who has no investment in whether or not this works, and is just gathering info, I find the counter arguments in this video to be more swaying. I will watch part 2 , but I think the experiments need more work.

[@jamessones4044]

Living by the sea gives me access to seaweed. The shop bought seaweed products are very expensive(I know they are concentrated a lot but still). After soaking it for a month with leaf mulch it has made the richest looking juice that I can’t wait to use to enrich my nans garden.

[@brianmcpartland3983]

This video is remarkably thorough. Even the printed verbiage is thorough. I'm very impressed with this host and his channel. By employing the scientific method, reality may be revealed. Well done!

[@AlbertaUrbanGarden]

Thank you Brian! I work hard to bring the best possible videos to the community!

[@DonnaldaSmolens]

I live in the desert so rainwater is not an option for me. However, I do have slightly salty well water and slightly salty alkaline soil. I use home made compost, but made my garden a bit large for my compost production and have had to use several amendments to produce food. Over time I believe my garden will be able to produce food and compost to replenish the soil every year. I use extracted compost tea just to get more bang for my buck from the compost ( I can't aerate it due to being off grid). I am so grateful for your very informative videos because it helps me decide what I can do to improve my food production which is my goal. Thank you.

[@AlbertaUrbanGarden]

+DonnaldaSmolens Large gardens are something that I have not spent a lot of time on but you can get a lot of bang for your buck. What usually I recommend here is to bring in a large volume of free and local organic material. Some times you can find local breweries or live stock operations that are always looking for a place to get ride of their waste. In the interim your compost tea method may not be competitive with other methods but it is better than nothing. Once your're soil is at a good point you are right compost needs drop to a manageable level.

[@DonnaldaSmolens]

thanks. My goal is to have fresh food year round so I grow a variety of plants. Also there is the challenge of over 110 degree F summer weather from May to October. I have been doing this for 3 years now and each year it gets better. People have been using the dirt road access from the nearest town to dump trash and I always stop and check for leaves for my compost pile. So far, I like Kellogg's Amend it is like compost with gypsum added which is good for my growing conditions. I also have to use chelated iron in the summer to help plants get the nutrients without getting salt burn.

[@AlbertaUrbanGarden]

That is excellent! I hope to grow food all year round as well :)

[@josephjohnson7684]

This video is funny. Each formula for compost tea is different and has vastly different effects. This is because the types of bacteria and fungus grown differ greatly based on not only the compost and food sources, but the concentration of nutrients used, the temperature and the amount of time it is grown. Aeration is usually used to culture aerobic fungi. The effect of growing a high fungal tea is to provide chitin to chitin degrading bacteria. This produces the compound Chitisan which activates the plant self defense mechanism producing class 2 and 4 chitinases. Chitinase degrades the cell wall of pathogenic fungi and insects. In high concentrations it will also cause a plant to put more energy into fruiting. Adding sugars can produce organic acids which can dramatically effect the solubility of the nutrients in the soil. The types of acids created will vary depending on the types of bacteria present, the nutrient in the media and available oxygen. The function of compost tea is determined by the type of organisms grown.

[@karnaag]

I agree completely with your analysis. Problem is Alberta approaches his "experiments", and I use that word loosely, from the perspective of "I'm just going to pull a notion out of my ass and by God I'm going to prove it's true no matter what." I don't even bother watching his videos anymore because of the pathetic way he does his research. That and the fact they tend to make my head explode.

[@joshuasaksa1641]

I would love to see a result of a well brewed tea vs. the simple tea you brewed up. I think the CFU is important but so is a break down of the diversity of species within the soil. I think you should see what types of fungi and bacteria are native to your compost and see what compost tea can do to increase other species. Another point for compost tea is foliar application to help reduce powdery mildew and other pathogens. Another consideration is that compost being time released has its limitations to the ppm it can release to the plants at any given time where as compost teas are for instant gratification and a boost to microbial life. I not sure that this simple test sways me.. I think more research needs to be done

[@AlbertaUrbanGarden]

I agree more research is needed to address all of the individual points you made. For that reason I spend some time researching some of those questions in part two of this investigation. Here is a link. There is still more research required for sure! kzbin.info/www/bejne/rpXOmXiAp5irZ6s

[@NaomiChambers]

Last summer, me and my husband went to a local lake that had been trained. On the shores were millions of tiny shells. I collected a bag of shells and added them to the garden, with the idea they would add calcium overtime.

[@AlbertaUrbanGarden]

+naomi chambers I have not researched it but it might.

[@alicejyi4705]

Please do all the tests on the claims.. This is a science. I will follow up.

[@sirugueteskani3966]

MICROBIAL (not only bacterial) DIVERSITY (not only abundance) is a well established factor that plays a role in plant physiology (nutrition, stress resistance, and disease protection) as well as in soil functioning (nutrient cycling, disease controll...). You are not addressing those issues, though you cannot talk about compost teas as a whole. Why wouldn't you make a real-world (not only lab' counts) test and see its effect on (at least one variety of) plant health or yield throughout an entire growing season? That would be a real contribution to knowledge that many gardeners and agricultural scientists would be delighted with :)

[@bhanwarabada6673]

Thanks Siruguet for your post which is more useful and without ulterior motives than the above video. Good bless!

[@turbonbc]

AACT is good to Kick-Start everything with newly built soil. After a while if the soil is full of micro-life and worms there is no need to do anything but Top-dress. Nice video well explained.

[@NosillaWilla]

WisdomTooth you can always add other things to your tea recipe, such as mealworms which will help your plant develop resistance to diseases

[@oneein9183]

You shattered my dreams of making compost tea for the first time. I was so excited lol.

[@AlbertaUrbanGarden]

Im sorry BUTTT now you can save time and dedicate it to enjoying your garden now!

[@OneYardRevolution]

Interesting results, Stephen. I think the replacement strategy is to just use compost and mulch.

[@OneYardRevolution]

+OneYardRevolution | Frugal & Sustainable Organic Gardening I was also curious why you chose to compare the nutrient value of compost tea to that of synthetic fertilizers. To me the important point of comparison would be to compost. The fact is that, in terms of nutrients, compost tea is just watered down compost.

[@AlbertaUrbanGarden]

+OneYardRevolution | Frugal & Sustainable Organic Gardening in my blog post for this video I do have more of a comparison however I was running into a 15 minute video which I was getting lost in. The issue with comparing a soil vs liquid is the methods are different for the analysis so you can not compare apples to apples. Anecdotally the compost had several orders of magnitude more nutrients and comparatively the compost tea had trace amounts that if added to the compost numbers and those combine compared to the original compost would not have an RPD of over 5 which is nearly identical.

[@AlbertaUrbanGarden]

+OneYardRevolution | Frugal & Sustainable Organic Gardening I also could not find any organic fertilizers when I was looking at this in the fall. so I used the results I already had.

[@OneYardRevolution]

+Alberta Urban Garden Simple Organic and Sustainable You wouldn't have to test compost tea to establish its nutrient value per volume is less than the compost it is made from. It is obviously less. After all, it is diluted compost. No new nutrients are created by brewing or steeping the tea. Therefore, I don't see any reason to use compost tea as a nutrient source. Just use compost.

[@OneYardRevolution]

+Alberta Urban Garden Simple Organic and Sustainable The problem with using a 20-20-20 synthetic fertilizer as the standard when assessing the nutrient value of an organic fertilizer is that EVERY organic fertilizer would fail the test. By that standard, all organic fertilizers are inferior.

[@mickyjames7610]

Clever Man...nice to hear actual results from your experriments.

[@AlbertaUrbanGarden]

Glad I could be of assistance :)

[@campbellpaul]

I would agree, a good hummus, top-dressed by a thoroughly composted material, is the best way to go. The important thing to learn here, is WHY bacteria is beneficial, and how it acts as the middle-man between nutrients and plant roots.

[@AlbertaUrbanGarden]

+alphamongrel I am leaning towards that recommendation a good mulch gets you everything you need. I however need to look into some of the claims made about compost tea to see if there are other applications ;) hopefully that lesson about the bacteria was not lost in the mix :)

[@campbellpaul]

Do you believe compost tea has a way of boosting plants natural defenses against disease? I would hate to see multitudes of gardens succumb if people abruptly stopped their normal feeding routine... I know Patrick with OYR really condemns the stuff lol

[@AlbertaUrbanGarden]

I have that comment on my list but am sceptical that compost tea would do something that a good mulch layer would not already do. We shall see more research is required!

[@matthewkheyfets1309]

The difference is that compost tea allows you to spread the same amount of compost over a wider area because the volume becomes larger due to the addition of gallons of water.

[@jkoeberlein1]

But it does no harm, right? I've always used compost tea on stressed plants and seem to get great results. Is this a case of confirmation bias?

[@jonothandoeser]

Yes.

[@mhkoo1]

An important detail is missed: bacteria do not release nutrient but simple store nutrients in their bodies. However, the nematodes and protozoa (each eats 10,000 bacteria per day) cause the nutrients to be released. One should test compost for protozoa and nematodes and can do that with a simple microscope that magnifies 400x.

[@bluemystic7501]

Mineral-derived NPK plant foods (or synthetic in your words) are a fantastic tool for the garden. However, most gardeners do not know how much or how often to use such a tool which can give bottled NPK foods a bad name. Once again, great test!

[@LewiPijnappel]

You dont make compost extraction with water. You make a plant extract with it and then airly activate it. This is a wierd test youre doing

[@duncandogster]

My understanding is that the reason for aeration is to promote the growth of beneficial bacteria and suppress the growth of anaerobic e-coli. Your experiment did not differentiate between these two bacteria types. A good real- world test would be to grow tomato plants in sand and see the difference in health/ growth rates between your organic 20-20-20, aerobic tea and anaerobic tea. Thanks for the video!

[@estebanfigueroa2050]

Great when greatly prepared. Like almost everything!

[@bryanpeixoto7087]

You need a minimum of 0.5 CFM per gallon to produce a decent batch of compost tea. However, as much as 0.8 CFM per gallon is recommended. A common fallacy is that an aquarium pump will suffice - this is far from the truth. The whisperer air pump you used isn't even adequate for brewing a cup of compost tea. This is why your lab results are so poor. Proper analysis of compost tea is done through a visual count through a microscope and not by plate count. True compost tea is an microbial inoculant. That being said, if certain food sources are added they will produce a fertilizer value in the end.

[@ForTheFuture50]

Bryan Peixoto....Well said.

[@tombryant4518]

Exactly.

[@mountaintophomestead7662]

I'm just starting to learn about this stuff, so pardon my ignorance, but what does CFM mean?

[@mikeinwtby]

Cubic feet per minute. Measurement of the pumps output

[@mountaintophomestead7662]

mikeinwtby, thanks :)

[@palletwoodstuffjuanfuentes8081]

Synthethic fertilizers are no fun in home gardening although they might be better in the long run compost tea is just plain relaxing to brew at home knowing that youre using natural readily available ingredients and just watching and waiting for your very own batch of compost tea that you know you made according to your recipe. That is the very core of home gardening so whether it has a bunch of microbes or very little nutrients no synthetic fertilizers will ever deliver that awesome satisfaction of watering your plants or vegetables with your very own homemade batch of pure compost tea

[@paulmaxwell8851]

At 3:42 you say "I have extreme reservations on the use of kelp in the garden" What do you mean? My wife and I have used kelp meal and soluble kelp in our garden for years, with great success..

[@gottheilj]

Kudos for this presentation. The bottom line is that a tea made from compost by any means will not exceed what the compost one started with. BUT, what about a tea made from another organic source such as fresh grass clippings, comfrey leaves, stinging nettle, and kitchen vegetable waste? Unlike compost, these are not already broken down by bacteria, fungi, nematodes, or worms large and small. Will an aerobic tea made from these sources digest them, releasing their nutrients faster and more completely than composting them?

[@AlbertaUrbanGarden]

Add that all to your compost pile and you will end up with more bio-available nutrients for your plants.

[@crazysquirrel9425]

in the spring you can 'jump start' soil bacteria by simply using plain old table sugar & water. You probably don't need to do this more than once or twice in the spring. Don't go crazy with the sugar either. Leads to mold and other undesirable things. Biggest benefits of compost tea is the minerals and trace elements you add back into the soil. Also, the microscopic bits in compost tea are 'bioavailable' to soil bacteria. The soil bacteria is what breaks things down for plants to use. Aeration adds precious oxygen to the tea. This is why fresh rain water is best. It already is saturated with oxygen. Cold rain water holds more oxygen than warm rain water. Using synthetic nitrogen can sterilize the soil of bacteria. The addition of mycorrhizal fungi can be of value.

[@davidthegood]

Very good work - I appreciate your scientific approach. I use long-fermented anaerobic teas now. Wish I had a local lab - it would be worth analyzing. And... I subscribed. Keep it up!

[@AlbertaUrbanGarden]

I will have to take a look into it my friend! thanks!

[@laconflo1613]

David The Good Get a good desktop microscope and compare slides/samples. From what I have seen... there is a massive difference in the activity and production of beneficial microorganisms and macro nutrients that increase with the application of organic teas. Composts vary depending on what material you add.

[@CharlesCherryWatercolors]

How about two side by side plots using tea on one and no tea on the other and see which one produces more?

[@allenchan6855]

Subscribed! I appreciate a fellow Alberta-ian, and one who follows the scientific principles. Have you tried comparing the CFU of the rain water vs diluted compost, vs compost tea? I'd think the compost tea is way more bio active due to the aerobic bacteria and sugar.

[@RichardAnfuso]

The microbiological testing results were only shown for a short amount of time. He mentioned that the level of microbes was at 12,000 cfu's/ml. it appeared to show that the results were actually greater than 12,000 cfu's/ml and at that dilution the plate was too numerous to count and was probably much greater than 12,000 cfu's/mL.

[@walkingmonument]

Great work Stephen! I'm super excited about this. Part of me was actually kind of hoping that you'd find that compost tea is everything they say it is and more but this is much more exciting cos I was considering making the investment in everything necessary for making aerated CT and now it sounds like I can keep cash in pocket. Woohoo! Looking forward to your next video. Looks like you've lost some weight. On purpose? Looking good bro!!

[@AlbertaUrbanGarden]

I am glad I could help my friend ! Keep your cash at least until my episode is out in 2 weeks. You are the first person to comment on my loss thank you. I have had some rough health issues so I am making changes. Gardening is central to it :)

[@Kowzorz]

Such a clinical presentation. Perfect.

[@AlbertaUrbanGarden]

I try to be engaging just some times you need to since things ;)

[@TomPalissade]

What do you think about the 95% of wasted water and nutrients in the soil? I'm most of the time using sub-irrigated containers to be sure nothing is wasted.

[@AlbertaUrbanGarden]

+Tom Tom the method you are using is the most efficient for water. It is great ! I adhere to water conservation techniques in my garden hoping to not waste any. That said I have an apple tree down gradient to catch what does leach out.

[@TomPalissade]

+Alberta Urban Garden Simple Organic and Sustainable I have made a blog few years ago on how to transform any kind of containers into SIPs, but i perfectly make the difference between natural soil and substrates in containers, I'm also using wood chips (Ramial chipped wood) for outside. plant-in.blogspot.fr/2011/03/bacs-balconniere-jardinieres-reserve.html

[@AlbertaUrbanGarden]

excellent how to my friend!

[@sideeyes7480]

Interesting subject matter that definitely strikes deep into the nervous system of certain gardeners. I am curious to see what the results will be when the entire experiment is completed. Great job exploring a touchy subject.

[@AlbertaUrbanGarden]

+Eric Glass as a man of science I don't like to hide for any issues!!

[@sideeyes7480]

+Alberta Urban Garden Simple Organic and Sustainable I totally agree. Science!

[@littlenugs9942]

Personally thought the object of compost tea and worm teas is not for the nutrients but for adding more diversity of old growth forest fungi as well as locally sourced microbes around your garden. To give your soil a more balanced biology which will result in less weeds and a more fruit filled harvest. Just starting to play with "knf" and "jadam" which uses no synthetic nutrients but does use plant extracts, as well as compost teas. Thus far I can't complain it's allot cheaper this way to grow food that's for sure

[@mikep490]

An older but useful video. There is a "concern" that compost breaks down. My friend said she uses tea to continue providing tea to give a "bump" to the original compost, but I'm not sure how you'd test that. Another note is that rain washes many of the nutrients from your compost. My friend built his compost bed on concrete with roof over the top. A small amount of the diverted rain was piped onto the compost pile. They were also trying to figure a way to capture the runoff and distribute it over their garden and yard. I assume that's similar to dairy farms where waste is liquified and spread over acres of growing plants. I did take advantage of runoff, one season, from a friend's rabbit farm where he captured a "slurry" of the runoff from the manure pile. (I filled a number of 35 gallon drums with this dense slurry as an easy way to boost 1.5 acres of grass.)

[@martysgarden]

You can also use an underground worm farm, it works very well when when your garden is mulched and you feed the farm. Cool video and thanks for sharing. Happy Gardening Marty Ware (from Australia)

[@AlbertaUrbanGarden]

+martysgarden That is a great idea Marty. I will have to look into it! Welcome back my friend! how are things down under?

[@martysgarden]

Hey there, me I am slowly getting better with my health. Taking some time though. Autumn is here, so it's not too hot. I will be working with trials on dwarf fruit trees and microgreens for a while. Thanks for getting back to and happy gardening this Spring Marty Ware

[@AlbertaUrbanGarden]

hope everything is alright my friend! enjoy fall Ill enjoy my spring!

[@4purecountry]

+Alberta Urban Garden Simple Organic and Sustainable . Earthworms, of any sort, are not native to Canada. Introduced Dew Worms (fishing worms) have caused great harm in many areas of Alberta. So far composting Red Worms do not survive winters, but with climate change, who knows.

[@AlbertaUrbanGarden]

I did in fact know that. At my day job we are dealing with it as the earth worms move into the boreal forest and destroy peat at a quick pace.

[@wrathofsocrus]

I've always thought long and complicated compost tea brewing methods was an unnecessary complication. Creating a habitat around your plants that harbors beneficial bacterial means any method of introducing bacteria should end up with similar results after several days in the new environment. Bacteria would flourish in a good environment and struggle in a harsh one. It does seem like if your compost tea hits equilibrium that you could evaporate the water to produce an organic concentrate. Besides killing off the bacteria there could be other losses as the water evaporates, and many times there are better methods for fertilizing your plants, but it could be a good option for specific uses. Either way, the results are very informative. Thanks for the great videos!

[@AlbertaUrbanGarden]

+wrathofsocrus I am glad you enjoyed the video my friend! You are right most companies that make organic amendments super condense them to get their NPK and other nutrients high enough. I too prefer the simple concepts.

[@Sorenzo]

I'm a lapsed lab tech. I think it's worth pointing out that the bacteria in a rainwater barrel are likely very different from the bacteria in the ground that produce fertilizing compounds, although there is a lot of overlap. So counting CFU's with a method that counts these different kinds of bacteria equally will not show whether either kind of bacteria is more relevant to the plants than the other. Also, I think the total count of bacteria is somewhat unhelpful. The plants don't eat the bacteria, but the biproducts generated by the bacteria. And the amount of these biproducts depends more on the input of nutrients for the bacteria than the count of the bacteria, since the bacteria will grow exponentially if given abundant nutrients. So it makes no sense to me to increase the total amount of bacteria, since the kind of bacteria that will grow in sugary water are not necessarily the kind that want to make fertilizer for plants, and the ones that like sugary water can potentially compete against the useful bacteria, rendering the solution much less useful as a fertilizer. My suggestion would be to get the compost tea to the soil regularly or not too long after extracting it from the compost, so that the bacteria that live in the soil can maintain a healthy population "in situ", since that's where they're needed (and since there will be less competition from water-borne bacteria). Intentionally increasing the amount of unknown bacteria just seems to risk ruining the batch or even risking adding a disease risk to your soil, unless you do something to ensure that the right kind of bacteria grow in it. (like adding cultures or chemicals, although that defeats the purpose)

[@jimsmij]

I've always been happy using my own, homemade compost and worm castings from my worm farm. Never bothered with compost tea. Thanks, Stephen for another thoughtful and thought provoking video.

[@AlbertaUrbanGarden]

I am glad my friend !! I follow the evidence !

[@Elifius]

how can you tell if the compost tea has no value if you do not grow plants with it ...... would also like to know what are the different temperatures which you brewed your compost tea?

[@crazysquirrel9425]

phosphorous and potash are both minerals. The synthetic part of fertilizer is made from petroleum. Potash and nitrogen can easily wash out of the soil but phosphorous doesn't and can have too much if not used by the plant.

[@themardogs]

Great job. This video was everting I needed to know.

[@MrVikingdane]

So basically forget the tea brewing and rock dust ?! That's going to save me a lot of time and money lol !! I know juries not out yet in the tea but thanks for all the scientific work you put in !

[@AlbertaUrbanGarden]

I am glad I could help !! Tune in 2 weeks from now to see what's up!

[@livingsoildynamics4630]

True LIving Organics! Hot soil! LIving SOIL!! NO TILL! Cheers!

[@tombryant4518]

The synthetic nutrients are also chelated, and readily available to the plants. The tea is not a fertilizer to feed the plants, the tea feeds the microbes. The tea has non chelated nutrients that need to be broken down (chelated) by the microbes which they trade to the plants for sugars that the plants produce via photosynthesis.

[@ironleatherwood1357]

I use comfrey tea and add compost to it. My plants love it!

[@hillcountryhick4639]

I try to limit open buckets of water around here due to mosquitos( x 100, Zika). Dry compost only for me. Did my 1st oncamera video today! Officially joined the online gardening community!

[@AlbertaUrbanGarden]

+HillCountryHick make sure to shoot me a link! stay away from Zika my friend! it is a little scary!

[@Tommyr]

+HillCountryHick Get a package of "Mosquito dunks" and put one quarter of one in you bucket(s). It is all natural and will kill any larvae in the water and stop new generations of mosquitoes.

[@hillcountryhick4639]

+Tommyr I've got some mosquito "bits". we have a fountain outside that we treat with that and also swimming pool chlorine. we might get rid of that this year with the Zika problem

[@alexoliman3198]

Great video. I wonder if you have considered experimenting with Comfrey tea as well.

[@iamorganicgardening]

Great Testing.. You cover all the ares. Well Done. Would you still recommend compost if someone was growing in Plastic pots?

[@AlbertaUrbanGarden]

+I AM NJ ORGANIC:farm:garden compost works magic even in plastic pots !

[@RafsKitchenGardenChannel]

Interesting experiment ;) Was considering using compost tea purely to spray leafs of vegetables just heard it helps to prevent fungi diseases to colonize leafs, but couldn't find any proof that it actually works anywhere. I think teaming with microbes should be first book anyone who is interested in gardening should read.

[@AlbertaUrbanGarden]

+Raf's Kitchen Garden the book is worth a read but as with anything take it wight a bit of scepticism

[@RafsKitchenGardenChannel]

Fully agree every information should be taken with grain of salt. What I think this book will do for beginner gardener though is automatically shift his attention to building soil life rather than choosing easy way and buying chemicals in supermarket, over-fertilize soil to grow those beautiful veggies that are shown in glossy gardening magazines.

[@AlbertaUrbanGarden]

you and I are on the same page!!

[@the0prynce]

This video was fantastic and very informative! I look forward to your next video on the subject as I've never used compost tea and was considering making some to use this season.

[@AlbertaUrbanGarden]

+the0prynce I am really glad you enjoyed the video! the follow up should be out this week.

[@creativewatercolor]

Awesome video, great information. Appreciate what you're doing. Looking forward to the follow up vid.

[@AlbertaUrbanGarden]

+Daniel Novotny Art Thank you for the kind comment! The follow up should be a good one!

[@Clogroup]

i would love to see this revisited using my recipe

[@rgobbler]

Thanks so much Steven for simplifying things for me and my garden.

[@AlbertaUrbanGarden]

Glad I could help!

[@VeganChiefWarrior]

Stephen, if compost tea isnt enough to be a fertiliser then where do plants get there nutrients from in nature? i thought dead plants had everything plants need to grow and that after it had all been broken down and made into tea that it would be like way stronger than any plant would need?

[@ThePatriotFallingDown]

Results will vary depending on the compost source imo. If you are using a steer or chicken manure in your compost, then I would say you will raise your risk of pathogens and risk of E coli. Vegan sourced composts should not have these variables. The majority of AACT I brew uses humus or premium vegan fed worm castings as the base of the brew outside of carb sources. Carb sources will play a major role as well, depending what monosaccharide or polysaccharides are available to the colonies to feed on. The types of beneficial bacteria and fungus are vast and from what I have learned will have different effects from different plant types. Glomus, rhizopgon, bacillus, trichoderma, scleroderma, suillus, laccaria, pisolithus are some of the different bacteria and fungus that I would have been curious to see CFU and propagules per cc counts to see what kind of biodiversity and numbers in testing, not to mention the nematode and protozoa content. The length of brew time will shrink biodiversity but increase population size of certain colonies that are more dominant. In my experience, microbial and fungal inoculation to soil plays a big difference in taste, yield, essential oil production, nutrient uptake and plant health. These break down complex compounds for better biological assimilation, and having higher strength in numbers to fight off pathogens and unwanted bacterias and fungus in the soil. Foliar feeding produces a biofilm that protects in the same way and can hinder downy mold hypae from spreading and keep away some hard and soft bodied pests (bacillus thuringiensis "BT" that we know kills caterpillars). Steeping compost without air will produce anaerobic colonies which may have bad numbers of the wrong bacteria and I would not suggest using that method. I am no mycologist, I manage a chain of hydroponic stores and have been gardening for 10 years and I am just speaking from the experience I have.

[@martysaskatchewan740]

yuuup. you nailed it.

[@bryanpeixoto7087]

you nailed it on the e.coli. The tea he brewed in the video is practically anaerobic. The air pump he used is for a 30 gallon "aquarium" which is for fish... not even enough dissolved oxygen to get a cup of compost tea brewed. Proper compost tea needs a minimum of 0.5 CFM per gallon. he is using around 0.0003 CFM so you can imagine why his tests showed such low bacterial count on agar plates - which isn't even a valid way of testing compost tea to begin with.

[@a.grayman6349]

Where to even begin, the entire experiment is seriously flawed from the start, and the premise does not speak to the core purpose of organic gardening. First, your not making fertilizer your making easily transportable beneficial organisms in a nutrient solution. This solution unlike regular compost can then be applied to the entire plant and benefits each part differently. Next as Bryan stated above, this "tea" has no where near enough air going through it, and the small amount that is is not even uniformly distributed. Next your comparison to synthetic soil poisoning 20-20-20 is just ridiculous. Of course these numbers will be higher, they are designed that way in a laboratory, but most is wasted as it is not able to be absorbed by the plants roots and just breaks down into some form of salt. Experiments of this nature are better left to the university's capable of actually conducting them properly.

[@PrairieJournals]

Very informative. Thank you for taking the time to test this theory.🇨🇦 Lethbridge

[@StreetMachine18]

The easiest strategy I recommend is to spread compost as a top dressing and then water or let the rain water your plants. This process will leach the nutrients into your plants roots. As grandma always says "No muss, No Fuss".

[@AlbertaUrbanGarden]

+StreetMachine18 I could not agree more :) simple is the name of the game !

[@yes350yes]

Not being an expert, but a user of the aact method. The question I have is that not all compost is made the same. So the quality of said compost , even using worm castings for aact which Is what I use could be different. But I can see your point that if the compost is good that the use of brewed tea might not be needed, but the issue goes on as we know many argue against your theory or tests.

[@AlbertaUrbanGarden]

You are 100% correct. Different composts may yield higher concentrations. But there is a much simpler way to use those nutrients. Apply them to the garden. I would love to see more citizen science on acct !

[@inchristalone25]

Thank-you for doing these garden science videos!! It is great to have some evidence for what we do in the backyard garden. So I guess compost tea was actually a way to save money for me because I was always applying it during watering times instead of just adding a bunch of new compost every year. I decided I don't like mulching as much as I thought I would because in springtime we get a lot of pill bugs that can also feed on the seedlings (yikes!). It'll be hard to give up the idea of compost extractions....! But it would sure save the effort :) I added a bunch of composted manure this year so I'll will try not to water with the compost tea and see how it goes.

[@AlbertaUrbanGarden]

What might help you is just do a small area with just water and compare it to an compost tea area. It might help ease you into it. I am glad I could help !

[@MrMac5150]

More testing. helps us understand, what is real and what is not. Good work.

[@AlbertaUrbanGarden]

I hope to help cut through the noise.

[@austin2842]

Stephen, what's your view on alfalfa pellets as fertilizer?

[@jassiuswise]

Wouldn't the answer to the question asked at 9:30 (why would you actively aerate compost tea at all) - be in order to get the beneficial bacteria (aerobic bacteria) as opposed to anaerobic bacteria? You said you bacteria test could not tell what types of bacteria it was registering, only the number. Just a thought.

[@zachbrown3872]

I’m curious why you don’t like kelp in the garden. thank you :)

[@eugene5088]

the experiment shows that 7 days (without bubbles) and bubble for 2 days produces the same result. I think I will just wait 7 days instead of bubbling 2 days straight.

[@hpmx704]

I always thought that the tea was to help increase the microbial and bacterial numbers in the soil, which help the plant take up nutrients, not necessarily a food source for the plant

[@AlbertaUrbanGarden]

That is correct my friend.

[@dhenbhoy]

Is it just me or would the temp make a difference .. bacteria growth is faster in summer is higher than winter .

[@danielleandrews3960]

My question is: if you claim to grow organically, why would you promote synthetic fertiliser?

[@bounsanongvongphachanh823]

can you do an experiment on "does synthetic fertilizer kill microorganisms?"

[@soner818]

Compost teas aren't designed to extract nutrients, but to grow soil microorganisms. A nutrient extract whether made from compost or manure is not a compost tea.

[@427SuperSnake1]

The problem I find in your test is that you used a limited number of sources for your tea. For example my tea has bat guano, kelp, alfalfa meal, yeast, worm castings and humus. And I use not a cheap aquarium pump, but a commercial pump with 750 gallon per hour flow. Now if you compare say my tea in diversity and nutrients. It would blow your tea out of the water and now you have something to compare to synthetic fertilizer. Compost with molasses is simply not enough diversity to contend with synthetic ferts. I mean it's like a synthetic fertilizer only adding phosphate but leaving out nitrogen and micro nutrients. I mean look on the bottle do they only use 2 sources of nutrients like you did with your tea?

[@AlbertaUrbanGarden]

+427SuperSnake1 as I mentioned in this video there was such diversity of options out there i chose to keep it simple and what most beginners would turn to. adding all sorts of products shifts it away from a compost tea and more into a soluble fertilizer. I also followed this up with a video evaluating the other claims and using peer reviewed research to assess them. here is a link to Part 2 kzbin.info/www/bejne/rpXOmXiAp5irZ6s

[@shashakeeleh5468]

Okay, as I've posted a number of times on these sites, and can't speak for Canada, but water treatment/MUDs do NOT use chlorine anymore, they use chloramines, which is a chemical combo of chlorine and ammonia, not the chlorine gas which would disperse into the air. The only way to reduce this, and fluoride is using reverse osmosis. Virtually ALL water providers in The U.S. use chloramines now, I'm sorry to say.

[@terrywallace5181]

Good video. Very informative.

[@shexdensmore]

Can you use honey instead of molasses as a sugar source?

[@harrellt1405]

Sir i read that molasses is not ideal in the compost tea because while you get a jumped in bacteria population it also just create a population reliant on the sugar food source which will not be found in the soil later on. Thats what i read, can you plz explain any counters to this.

[@427SuperSnake1]

The problem I find in your test is that you used a limited number of sources for your tea. For example my tea has bat guano, kelp, alfalfa meal, yeast, worm castings and humus. And I use not a cheap aquarium pump, but a commercial pump with 750 gallon per hour flow. Now if you compare say my tea in diversity and nutrients. It would blow your tea out of the water and now you have something to compare to synthetic fertilizer. Compost with molasses is simply not enough diversity to contend with synthetic ferts. I mean it's like a synthetic fertilizer only adding phosphate but leaving out nitrogen and micro nutrients. I mean look on the bottle do they only use 2 sources of nutrients like you did with your tea?

[@yes350yes]

+427SuperSnake1 Yes and this reinforces my point in a similar quote above. Agreed!

[@TheNeonMind]

Agreed. Needs a better air pump and a more diverse food sources. Try again, Alberta Urban Garden Simple Organic and Sustainable.

[@AlbertaUrbanGarden]

watch part 2 of this video the science is just not there kzbin.info/www/bejne/rpXOmXiAp5irZ6s

[@historias-v6u]

hellou, 427SuperSnake1, after made a buck of compost tea, how long you should finish it before bacteria starts to die?

[@427SuperSnake1]

Yami Club I use it as soon as I turn the air pump off. There is really no reason to keep it when you can always make more. And once you turn the air off the beneficial bacteria will start to die off from lack of oxygen. So the sooner the better

[@wongelfski4681]

Oxygen levels are too low in your buckets for bacteria and fungus to proliferate. I commonly see this issue when people are using air stone pumps. It would be interesting to see what would happen if you directly injected oxygen into a bucket for 72 hours that had been inoculated. There should be a very thick head at the top of your tea when it is finished much like what you would see on a beer. Also be sure to allow the chlorine to dissipate from the water for several days before you actually add compost or you will kill everything. The point of introducing fungus and bacteria to soil is to establish a mycorrizhal mesh and to fortify the soil with aerobic bacteria. Note, if you are using commercial fertilizer which is not organic you may be actually harming the bacteria and fungus which has established itself in the soil. Again, Compost tea lets you jump start a symbiotic relationship between fungus,bacteria, and plants roots. It is not a quick fix But rather a long-term investment for the health of your soil and plants

[@kreeetin]

Absolutely. Fantastic. Video