Anyone scaled up compost tea production?

I watched the movie “The Biggest Little Farm” a few weeks ago, and generally enjoyed it. One thing they show is what I think was a fairly elaborate and large scale compost tea producing system.

I have about 10 acres of recently cleared and newly established pasture that is just begging for a jump start to soil life, and about 20 acres of established hayfield that could definitely use a boost without using chemical fertilizers.

Has anyone scaled up a compost tea operation where you could feed significant areas with regular doses of compost tea?  Did anyone else see that movie and understand how they did it? How would one spread/spray it?  Would really love to juice up my soil biology.

Thanks in advance for any ideas, suggestions, or pointers.

Artie,

I made about 25 gallons at a time. To make more would require a vortex brewer, and that project stopped when I looked at the price of the vessels. I found one that I would have to modify and fix and it was still about $1000. I know you are basically hitting the reset button, and it might make sense. I get so many free woodchips it was far more cost effective to just lay chips (I have probably done around 400 yards at this point) but compost tea was the backup plan.

What I figured I needed was :
A large pile of compost and a follow-on pile for the following year. This is the starter culture basically. Needs to be very degraded and screened. Hardware cloth works well in decreasing sizes for screening.
A large vessel preferable with a conical bottom for brewing. There are some small beer brewers either switching to stainless or getting out of business that I targeted. Custom kits are available and expensive.
A pump to create the vortex. This should move an awful lot of water because the vortex oxygenates not the air mixed post-pump. I want to say I was thinking this one would be adeqaute and has 2" in and out ports. Anything smaller would not generate a vortex on a 250 gal brewer. There are few 120v pumps that can move enough water.  
Make cleanable screens for the draw and fab the PVC inflows (there are lots of images on the web)
Distribution is a separate issue:
Tank fed by gravity if possible
A boom sprayer with wide open (no sprayer nozzles) would be great. Or fab the boom from  PVC with ends capped and appropriate sizes drilled. I think I used 1/8" on my test (which involved a trash pump and less than optimal brewing vessel) bigger is fine you just are looking for gentle wide application.
If you want to be super cool pressurize the distribution tank to avoid tearing the strands with a pump.
Do it in cool temps in the evening to get max survival preferable before or during a rain.

Then you have to tell us how it goes. I was planning on 250 gal/acre every couple months. More seems better to me.


I have not seen the movie.

Your big limit, like TJ said is going to be cost. If you buy premade models than a 100 gal brewer can easily run $700 with the pump. The biggest brewer I have ever personally seen in action made about 900 gallons of tea at a time in an 1100 gallon water tank (about 7 or 800$) and it made use of a massive air pump that probably cost 500$ or more as well as a good bit of plumbing. Probably the cheapest way to go if you want to make an unlimited volume of tea is to find a flowform model for around $1000 and buy a 2 or 300$ biosafe pump. With those two things you could make compost tea on a volume only limited by how large a water reservoir you can source. What's your budget? that's likely to be the limiting factor

S,

I have a pretty big air pump I want to say 14 GPM or >the volume being brewed. This was in a 20 gallon container not used to capacity. I still struggled to prevent it from getting skunky. The vortex should prevent bio layers from forming and the worst areas for bio layers were on the air tubes. The vortex means you don’t Have those stagnant areas. In terms of the energy consumption I think air pumps start losing ground. The amount of oxygen available is limited only by the surfaces of the induced vortex which is very high.

The other way I thought about going was an old 1 hp garage door opener motor with a paddle installed where the gear driving the door would go. That should be able to generate a vortex after a few minutes in a large cylinder. Just hard to drain and clean without the conical bottom. If there is a site to get those at the price you quote I would be interested.

Hey TJ -

I just looked online and it appears we got an amazing deal on the 100 gal vortex brewer I was using. It was definitely home mad and not as nice as most of the commercial ones that I found but it was also significantly cheaper. I might try to go wriggle it loose from the unscrupulous landlord who sort of seized it after all. I believe the pump we were using was an ecoair 5 commercial air pump that does 1400 gallons/hour, pretty affordable at around 100$ usually. The company makes on size larger, ecoair 7, that I think pushes air at close to 3500 gallons/hour and is still under 200$.

My main questions are, what is your budget? How much fabricating do you want to do? And what is your application capacity? (how much aerated tea water can you apply per hour?)
oops, those questions were more for Artie I guess. For the cheapest way that I make the volume you're talking about TJ is a 55 gallon pickle barrel with pvc plumbed down to a simple manifold at the bottom of the barrel with a male hose barb out the top. You can get really good aeration with a pretty cheap air pump (I know the ecoair 3 will work wonderfully for this size) and 50 gallons can reasonably be diluted into 200-500 gallons of water (some folks even say 1-20 dilution of tea to water is functional) to be spread around.

Thanks TJ, S, some good food for thought. Maybe I should just start small and gain expertise. But, given the gallons per acre needed, as you point out TJ, small scale doesn’t seem to get me there very quickly.

I suppose the cost of a larger system is relatively low compared to the ongoing cost of chemical fertilizer, so maybe I shouldn’t let sticker shock from going bigger once I get more comfortable with it.

Artie, I did the small system for my wife’s little yard as a proof of concept. I used it non some patchy area after I had done the yard. My first few attempts were great and the problem with the nonconical brewer was that the biofilm buildup on the PVC tubes I used instead of air stones. Air stones are impossible to sterilize without bleach soaking. I could just wipe down the tubes in between brews and limit the starting culture causing the films but again it is almost impossible to really sterilize in between brews. In my layman’s opinion, the best defense is a good offense- more oxygen better distributed. The pvc pumped a lot of air through but without enough agitation. Vortex would be a big improvement with chaotic motion. I may pick it back up eventually but I am doing a mile at a time of perimeter fence and the addition of grazers in my opinion is more important than the tea. Especially because I have the wood chips.

This thread inspired me to do a little more searching.  I made this unit. Seems like the agitation is good.

I have a 300 gallon ibc tote on a trailer that is pulled by my tractor.  There is a pto pump that connects to it. This is a decent way of getting it out on the land. I need to figure dilution rate. 10:1 would fill the tote but no reason to fill the tote to use it.

wayne fajkus wrote:This thread inspired me to do a little more searching.  I made this unit. Seems like the agitation is good.

I have a 300 gallon ibc tote on a trailer that is pulled by my tractor.  There is a pto pump that connects to it. This is a decent way of getting it out on the land. I need to figure dilution rate. 10:1 would fill the tote but no reason to fill the tote to use it.

That looks awesome Wayne. I would just dilute to the total volume you want. Many people say you can dilute to 20:1 so even filling the tote would be fine I would think

Also, looking at that air pump, if you wanted to you could just insert that agitator and pump straight into the 300 gallon tote. I have used those pumps to make tea that way (the totes are way harder to clean though). you could also get a pickle barrel and make 50 instead of 30 gallons at a time if you ever wanted. Those pumps are amazing

I've got a similar set up as Wayne, and a small plot of land to activate. I haven't used it so far, because of time issues and i understood you will have to add a lot of organic matter first or at the same time if you want to kick start the soil biome. It's all right adding all these bottom dwellers in massive amounts and diversity, but they will not flourish if they don't find something to chew on. A micro biologist told me it's no use even. How do you see this?

Are you asking about the benefits of compost tea? I am mixed on it. I am no scientest and don't own a microscope. Some things come to mind though.

If you multiply in a controlled environment then put it out in nature without the air and food supply,  will that large explosion die off? It seems to be likely, but, is the dieing off giving a result like when plants die and feed the network. I don't know. I also don't know how to quantify if it is a benefit. If i have to water this area mechanically (ibc tote with pto pump) anyway, this  takes very little additional effort for me. It also allows seawater to be broadcast also, just dump it in the ibc tote.

The area i want to apply it in has been earthworked into a terrace and the slopes have been heavily mulched with woodchips. The flat areas have been mulched with hay and horse manure spread on it also. Sloped area will have trees and herbs. Flat area will have annuals, grapes, and other vining plants as an arbor is the border of the flat.

Wayne, I am with you on this. I think it’s has a role in kickstarting dead ecology. I have an area that was absolutely sterile growing only occasional wild onions and crabgrass and I used some high test compost tea on it . It now has a little grass but nothing extravagant. Where would it be if I hadn’t done that but still run the chickens and laid down rock dust and chips? Hard to say.

From a perspective of skepticism I think adding biology without all the pieces in place for sustainability of those organisms seems like a temporary solution. If it can lead to production of a lot of biomass and penetrating roots and so on it would have a role. I think the OP is in a large scale regeneration and can’t cheat like me and just add biomass to instantly get 5% organic matter (which based on the degradation curve will hopefully be about 2% durable carbon). He really has to grow that biomass over a few seasons.

From my layman's perspective, this is the exact same problem that Mike is dealing with in his compost pile. There is always ALWAYS a rate limiting reagent in a process that keeps the thing from growing exponentially. It could be water, nitrogen, in VA phoshate is a big problem, microminerals, sunlight, ad nauseum. As you manipulate one factor even if you get it right another one pops up to limit your reaction. This is the reductionist approach though, and that has problems.

I use compost and the compost tea to use the little beasties to fix some of the problems I can't see. I have a crap microscope and fifty other things I need to do (bled brakes on one vehicle this morning and have to replace a fuel pump or relay on another so thats another ? hours) and so I outsource that stuff to my beasties. I eyeball the big things and try to fix what I think are major factors- water retention/drought prevention, availability of minerals in some modest concentration, root pruning and tree death in areas trying to succeed to junk forest. Those are all super shotgun things. I can build those in at scale and do no testing. I can get my head around those too.

For the rest, I assume the micro and macro beasties are going to figure it out. My early priority was animals on the land, rotating and recovering. We had chickens way before I was comfortable with it. The rotation is time consuming, but I think it has paid off. After the #$@# preimeter fence which is consuming my life, it will allow more time consuming sheep rotation. But the amount of beasties goes way up, and I control the rotation and recovery (unlike the hoof rats eating my silvipasture to nubs every 3 weeks). I predict in two years this will be crazy verdant. The sheep will provide the disturbance this place has lacked. When that isn't enough, in come the piggies or cows or something.

The compost and compost tea seems like an accelerant, just like throwing down nitrogen. But it has a spectrum of accelerants in fast and slow forms, so there is no "bloom and bust". How is this different that providing the elements of a compost tea (by my reading: biota, energy source, mineral source, oxygen) in the field to react at a slower rate (because oxygen is limited versus the tea brewer)? I think you can get there either way, just takes longer with the in place model. How much longer? I think that depends. I subsoil the chips in (This is 6" of chips initially) down to 2' (!) with a subsoiler on keylines I had to fabricate myself (thanks Travis for making me acquire another time suck skill) that also is ripping out the sweetgum roots trying to re-establish the junk forest. This solves about three issues- water retention, low oxygenation at depth, low carbon/energy molecules at depth, low mineral supply in the A horizon.

So I am disturbing very greatly right now, then I have to move the biome forward. I could use compost tea but I am going with herd animals. I get a yield out of it, and it's good for the land including the inhabitants. I think the OP is in the same bind, do you put out animals before the biome is recovered? Alan Savory would probably say ASAP, but at a low density, which is hard to pay off the fencing. The tea might give enough forage to make it work in a season (that's what I was planning on doing before I got all the chips) with cheap annuals like sorghum sudan and sesbania. Huge disturbance followed by annuals followed by the perennials that naturally make their way in like Greg Judy and Joel Salatin have documented. I think that model is well proven. Joel has interns and can afford the up-front fencing and management but I don't have the time. Greg has the system and the acreage to run a huge amount of cattle for a couple days (and he seeds annuals before they go in the first time). I like the Greg Judy approach greatly!

I have scaled up my worm tea production.   With a typical medium size aquarium pump i could do maybe 5 gals per day.    Then I purchased an 18.5 gpm air pump from amazon and a  32 gal trash can from Home Depot. Now I can make 30 gallons overnight.  The photos shown have the new pump but they were taken prior to the purchase of the trash can.  The video shows the bubbling intensity,  but in the deeper narrower can the intensity greater still,  as the bubbles accelerate as they rise. With my increased worm castings production of about 3 cu.ft per month,  I can make virtually unlimited amounts of worm tea.  I guess that i currently have about 30 lbs of worms working for me.   I need to soon source more organic material for the wormies to process.

Hmm the mp4 bubbling video cannot be attached.  Hmmmmm?

Sincerely,

Ralph