Where Compost Extract Fits into a Regenerative System

Jesse: We're here in beautiful East Tennessee at the Tsali Notch Winery sampling some of their delicious muscadine wines, and talking today with Simeon, our soil scientist, about the practical considerations of making compost extract.

The farmers we work with are doing what they can with cover cropping, minimizing disturbance and chemicals, and adding animals as they're able. Where do extracts fit in with those other practices?

Simeon: The main purpose of an extract is to rebuild the microbiome — to get the signaling molecules going again in the soil. The best benefit comes from applying it on the seed, as a seed coating or in-furrow. In those first three or four days of a plant's life it’s really important to get the microbiome and the plant interacting. It's very hard to apply solid compost across a lot of acres, and with teas you don't have the diversity you'd get from an extract, and it’s harder to scale. Extracts fit the bill: you get the diversity for the crop, and it's something a farmer can implement alongside cover cropping and minimal tillage.

One of the six principles of regenerative ag is to integrate livestock. Most people think of livestock as cows, sheep and pigs, but I like to think of extracts that way too. If you can't integrate the big livestock — which are very beneficial — at least you can integrate the small microbiome livestock, build that soil out, and get a functioning ecosystem again.

Your Extract Is Only as Good as Your Compost

Jesse: If someone's thinking about setting up a compost extract production system in their operation, let's talk through the considerations. Start with the compost — the material you're using. What do they need to know?

Simeon: Extracts are only as good as the product you start with. Depending on where you are in your transition and what your end goals are, you can tailor your compost: what feedstocks you use, how long you let it age, what moisture you keep it at, whether you add worms, whether you add spores, whether you grow cover crops on top of it. You can slowly evolve your compost to fit what you're trying to bring back into your ecosystem. If you're low on predators like protozoa and nematodes, you can make a blend that favors protozoa and nematodes, so when you extract it you have elevated numbers going out to build that soil.

Most soils we're working with, especially in the beginning, we're just aiming for as much diversity as we can get — fungi, bacteria, protozoa and nematodes in a very balanced compost. Three to five years down the road, as that biology builds and the numbers get where you want them, you can start honing in and targeting specific organisms. That's when you make piles aimed at whatever group you're trying to populate back into the soil.

Growing Cover Crops in the Compost Pile

Simeon: One thing that's become very popular in the composting space is growing cover crops or living roots in the compost, to get the rhizophagy cycle going and prime that compost with the biology needed for whatever crop you're growing. If you're growing a diverse cover crop out in the field, you can plant that same cover crop into the compost itself, get the rhizophagy cycle going, get the plant–microbe root interactions going, and then extract it, liquefy it and get it out there. It'll be much more ready to associate with the plants in the field. Same if you're growing corn or wheat — you can grow that in the compost.

Thermophilic, Vermicompost, Johnson-Su

Simeon: There are three main composting processes people are probably familiar with. First, you do need the thermophilic, hot composting stage, so you kill the weed seeds and the pathogens. From there, if you're good at making a thermophilic pile, you can just let it age out. If you had a good recipe, the right moisture and air, you'll have a very biocomplete compost at the end.

Alternatively, you can take that thermophilic compost and run it through a worm bin. Vermicomposting elevates bacterial diversity and has less effect on fungi and protozoa; you want the fungi and protozoa there already, because they're not going to grow much in the worms. But bacterial species get really diversified and the worms promote a lot of the plant-beneficial bacteria. Dr. Zach Jones did a study across, I think, a hundred different feedstocks, and it didn't really matter what went into the worm bin: they saw the same 10 to 15 beneficial bacterial strains in every single compost. The common denominator was the worm's gut — that's what's inoculating the product. And if you're using local food sources, that translates into local indigenous organisms that survive in your environment, whether it's hot, cold or temperate. You want to be growing it in your environment so they adapt — the whole science of epigenetics and adaptation to the environment.

The method for fungal dominance is the Johnson-Su. That's a static pile: you mix a recipe, get the moisture right, put the tubes in and let it sit. You keep it wet, and after a year or two, you have a really nice, almost clay-like substance with high fungal diversity. If you want to push protozoa, you can add an alfalfa feed to drive those numbers, and there should be some nematodes in there as well, but that method is mostly about pushing fungal dominance.

So what a lot of guys do is take a vermicompost and a Johnson-Su compost and mix them together, get the bacterial and fungal diversity in one product, and put that out at one or two pounds an acre. Composting is a really important first step to extraction, and if you can't make your own, there are reputable sources available. We sell Grozome product, a bamboo biochar–based compost made in North Carolina, which has a really good balance of fungal diversity, protozoa, nematodes and bacterial species. It's a hybrid between the thermophilic process and the Johnson-Su: they turn it two or three times to start, then it cures for four to six months. There are over 4,000 different species in it, so it's a biologically complete compost as well.

Testing Compost Quality and Contamination

Simeon: There are a lot of other ways to do it — biodynamic methods, JADAM methods — and a lot of other materials you could extract to get diversity, including anaerobic organisms. Composting is an endless topic, but the important thing is to check the quality of your compost so you get a good extract at the other end. There are only so many parameters we can control in the extractor, and we can't magically manufacture microbes inside the extraction system. It has to be there in the starting compost.

Jesse: I think this is one of the biggest paradigm shifts for people — realizing that "compost" is one word for broken-down organic material, but there's a whole range of outcomes depending on a lot of factors. When you're keyed in on the biology, it's really important to know you have a good microbial population in what you're using. What are some good ways to check that, if you're sourcing, say, mushroom compost from a local outfit?

Simeon: It depends on how scientific you want to be. You could get a microscope, learn what you're looking for, and do it yourself. There's the Microbiometer that gives a quick indication of the fungal-to-bacterial ratio — but don't t compare Microbiometer numbers to what you get on a direct microscopy test. And there are labs you can send samples to, whether that's a Soil Food Web certified lab or a DNA sequencing lab for a full genomic reference.

The key with any test is to be consistent with the methodology, and not to compare DNA sequencing to microscopy. They're two totally different tests, and different indications of diversity and quality. Take them as two separate tests, and only compare direct microscopy to direct microscopy. If you're testing four different compost samples to find a good one, use the same method on each so you can actually compare them and see which is best for what you're trying to do.

The other mind shift in the extract world is that we're not viewing compost as a waste source, and we don't need a lot of it. If the main goal of your composting operation is waste disposal, that's fine — make your bulk compost and use it where you need it. But then take some aside and make a really controlled, high-quality recipe you can extract from. You don't need much to make an extract, even at big farm scale.

The other part of composting is making sure you're not sourcing contaminated materials. That's another benefit of having your own microscope — being able to do the forensics as you go. You can have the perfect recipe of wheat straw, oat straw, alfalfa and wood chips, mix it all together, get a nice heating cycle, and then check it at the end and there are no nematodes and no fungi in there. That could be because there was a fungicide on one of your inputs, or herbicide contamination, or antibiotics coming through if you're using manures. You have to be mindful about getting really clean materials. They don't have to be organic certified, but they need to be free of chemical contamination so you can create the microbiome. And the reason you test is that you can catch a problem early. That's the difference between waste-disposal composting and biological composting for the biological health of the compost.

Water Quality: Chlorine, Hardness and Filtration

Jesse: Once you've sourced your compost, the only other ingredient in an extract is water. Talk us through what people need to be aware of — water quality, water quantity, things like that.

Simeon: Water is a really important part of the extraction process, and there's a lot of research still to be done there. But the one thing we do know is that we don't want chlorinated water. Chlorine, chloramine, fluorine — you don't want any of those, because they're antimicrobial. They're in the water specifically to stop microbes from growing in our water system. If you're on city water, test for it and see what you have. If it's chlorine you can off-gas it, or add humic acid. If it's chloramine, you'll need some kind of filtration system to remove it.

The other thing to watch for is high carbonate — calcium and magnesium, the hardness of the water. Above 100 to 150 parts per million you get nutrient tie-up, and it becomes an adverse condition for the microbes and for the minerals you're trying to add with them. You end up less efficient with that water, and you don't get the benefit you should from the nutrition or the microbiology. The way to mitigate calcium is reverse osmosis filtration. There are carbon filters and other options that start reducing it, but you never really eliminate it without RO.

If you're on a well with good water, or on rainwater, you might not need to filter. A lot of city waters need filtering, and RO is a really good option, though it gets expensive. You want to find the trade-off between gallons per day and storage. You might buy a 2,000-gallon-a-day RO unit and a 10,000-gallon buffering tank, sized to your peak week. If you're making 10,000 gallons of extract, you can use the smaller unit feeding a big storage tank, instead of buying a filter system that keeps up with the extractor itself — that gets super expensive and it isn't necessary.

You can use ascorbic acid or humic acids to neutralize the calcium and some of the other minerals in the water. Then there's pH: you want to mimic what's in the plant and in the soil, so aim for around 6.5 to 6.7 in an extract. And you want to be low on sulfurs, irons and some of the other minerals.

If you're starting out, I'd highly recommend getting a water test, seeing what's in there, and then deciding whether you need to filter. Invest in the filter — it'll pay for itself in the increased efficiency and efficacy of the application you're making.

Rainwater can be good, but the caution there is: do you have lead on your roof? Is there rust on your roof? Are you storing it in direct sunlight where you can get algae growing? There's a lot to think through to keep a good-quality water source.

Extraction Basics: Dilution and Application Rates

Jesse: Once you have your compost and water and you go to do the extraction, what are the considerations in using water to get the microbes out of the compost and into a liquid? How much are you screening the particulate out, what PSI are you extracting at, and what are the different methods — why have we keyed in on the water jet process?

Simeon: Compost extraction can be as simple as putting a bit of compost in a five-gallon bucket, filling it with water and hitting it with a paint stirrer, or even hand-massaging a bag, depending on your scale. Most guys are looking at one pound of compost to five gallons of liquid, which is a pretty standard dilution, but you can run whatever dilution you want based on the quality of the compost and how many pounds you're aiming to get out on the field.

What we recommend most people aim for is two pounds of compost per acre per application in row crop settings. In mixed vegetables or turf you can increase that to five to ten pounds an acre. And even in row crop you can go higher, based on scale and what the compost costs you.

The basic constraint in any extraction method is how much time you're willing to spend. If you have all day to beat up a five-gallon bucket with a drill and put it out on one acre, that's fine at that scale. But what about a thousand acres? Then you need to start scaling these processes.

With the batch process, you put a tea bag of compost into a hopper, or dump it into the cauldron, and bubble it for a certain amount of time, circulating water through whatever system you have. There are vortex systems where you circulate a lot of water, air systems where you bubble it, and systems that combine the two. It's all using the jostling and circulation of that water to jar the microbes loose from the substrate into the liquid. Then the other step is filtering, because obviously we can't put half-inch chunks of wood chips through a sprayer or a seed drill.

Screening and Filtration Trade-offs

Simeon: You want to screen the extract as coarsely as possible. I'd rather see you apply an 80% quality product and get it out on the field than make a 100% quality product and get none of it out because you plugged your tips. You will have to make trade-offs. Ideally you'd take that whole solid compost, suspend it in water and put it out, but that's not feasible with most of the equipment we operate — unless you have a really big broadcast nozzle and can put out quarter-inch chunks, in which case, great, do that. Most people are running conventional spraying or in-furrow equipment, so we need it filtered down. If you're using a tea bag, it's coming through a 40- or 50-mesh screen, and some systems have secondary screens.

We've engineered our system with four screen options — 40, 50, 60 and 80 mesh — so depending on how you're applying it, you can filter it as fine as you need right at the extraction point and not worry about filtering any further downstream. Conventional systems running 80-mesh screens on big boom sprayers, or an exact apply planting system on your John Deere planter, don't like any amount of sediment. We need it as clean as possible, and that's where a secondary filter may be necessary. A lot of guys will run it through a settling tank, let the heavy particles drop out, and pump off the top.

Water Jet vs. Batch Systems — and Extract vs. Tea

Simeon: The main benefit we've found with the water jet technology is continual production. Every other system is inherently a batch system: whether it's a big stainless cauldron or a thousand-gallon brewing tank, you put in a set volume of compost, fill it with water, circulate it long enough to get the extraction you're after, then clean the system out and get it ready for the next batch.

A lot of those systems can do either extract or tea. The only difference with a tea is that you run the air for 24 to 48 hours — but then you're selecting for the eight or ten strains of bacteria that do well in high oxygen with those food sources. You gain population, but you lose the parent diversity of the material. With extracts, we're trying to maintain that parent diversity of the material we started with and just get it into liquid form.

How much time you're willing to spend filling a tank with water, aerating it, extracting and then filtering it to get an applicable product — that's what sets our equipment apart. It doesn't matter which size machine you buy, from the X100 to the X350; you get continual production. It can run for one hour or ten hours in a row. As long as you keep the hopper full and have your speed set, you can make whatever volume you need with very little manual effort.

The other side of it is efficiency. We did a study with Dr. Elaine at the Soil Food Web against a cone brewing system, and we were getting basically the same extraction percentage — comparing the compost going in to the waste product coming out and seeing what was left. We're getting 70 to 80% efficiency across all four main groups: bacteria, protozoa, nematodes and fungi. But what really stood out was the number of organisms we can extract per hour. Our machine does that extraction in a minute and a half to two minutes as it runs through the auger, versus a cone system taking a full hour. We can move a lot more material through and make a lot more gallons of extract out of that compost, at the same efficiency as the tea system.

The other thing to consider is stabilization. If you elevate the dissolved oxygen in that water, you start elevating biological activity, and that can reduce the shelf life of your product. Keeping it in the static form we use with the water jets creates a really stable product you can store for a long time in extract form.

You might want to start with a batch system. They can be fairly cheap to build and a lot of our customers started that way to prove it to themselves. Once they want to scale to their full acreage their time becomes valuable, and they look for a system to keep it efficient. If it's not easy to do, you're not going to do it. The batch process is complex: you have to think a whole day ahead, get your brewing system set up, get your air going, make it the night before. With our X350 you can come in the morning, and while you're filling your seed drill you can have a thousand gallons produced in an hour. While you're out in the field you can even put it on a timer so it keeps a bulk tank full while you're planting or spraying, and you just come back, fill up and keep going. That's how we can get it done across five acres of turf or a thousand acres of row crop.

Storing Extract: Shelf Life and Conditions

Jesse: You mentioned the ability to store extract because it's more stable. What are the guidelines for storage — the conditions you need, and how long would you expect it to be good?

Simeon: Storage really depends on the goal of that extract. If you're running it for the humics and fulvics, the humus compost side, and you're not viewing it as a living organism, you have a much longer shelf life, because you're not trying to keep organisms alive. Those growers can hold it for five, six, seven months.

If you're viewing your extract as a living organism and you want to maintain that diversity, ideally you make it and use it as soon as possible. But if you do need to store it, or you're making it a couple of days ahead to keep up with production, you want to be extracting into a cone-bottom tank and vortexing the product once a day to maintain dissolved oxygen at five to eight parts per million.

You want it out of direct sunlight, and temperature controlled if you can manage it. If it's not temperature controlled, just be aware that as temperatures rise, your storage window shrinks: warm water is more active for the biology and has less capacity to carry dissolved oxygen. Ideally we want to hold 70 degrees Fahrenheit and stay out of direct sunlight, and then you have about a two- to three-week shelf life with all the big groups — fungi, protozoa, nematodes — in pretty good numbers. The bigger predators, the protozoa and nematodes, are the first to fall off, then your fungi, and in the end you're left with a bacterial solution, which is basically what a tea would be right away anyway.

Try to make it and apply it, but if you have an equipment breakdown, or it rains — things happen, we understand that — you can store the product instead of throwing it away. The other nice thing about a flow-through system is that if something breaks, you turn the machine off, fix it, and start it back up. You don't have to empty out a whole brewing tank, disinfect it and get it ready for the next batch.

Application: Food Source, Seed Coating, In-Furrow

Jesse: There are many different contexts where you can apply extract — row crops, turf, orchards, vineyards. What are the common ways of applying it, and the application rates that go with different methods or cropping contexts?

Simeon: Before you apply, you always want to send your extract out with a lunch pail of food — a food source going into the field. It's really beneficial to add molasses, humic acids, fish hydrolysate, squid juice; the kelps are beneficial too. A lot of guys will add nutritionals alongside the extract as well, so depending on how you're applying, that might be micronutrients for a foliar application or a seed starter if you're going in at planting. That food source is important, and you want to add it to the extract right when you're ready to get it out in the field.

The first way to get extract out — and probably the best ROI and the most efficient — is seed coating. It can be as simple as a five-gallon backpack sprayer dribbling into the auger as the seed moves from your seed tender into your seed drill. As it moves up the auger it gets that coating and dries off, so you don't get clumping. Most guys aim for about six ounces per hundredweight of seed, six to nine ounces, so you're not getting it too wet but you're getting good coverage of biology. For that application you want the extract as concentrated as possible, because you only need a couple of gallons for a lot of acres. And since it doesn't have to go through a spraying system, it can be chunkier and coarser and still be easy to apply. If you're putting it through a seed treater or a more advanced treating system, you may need to filter it down. But the seed is the first place to get it out.

The second is in-furrow. As you're planting, if you have a liquid system on your drill, I highly recommend running extract along with some of your nutrition, so you get the microbes and the minerals together. That creates a much better environment: better root growth, and plants better able to withstand heat stress, drought stress and root stresses, with more nutrient availability. They're just healthier plants, so when diseases come through they don't get knocked out as badly. That's the whole concept of regenerative ag — a healthy soil creates a healthy plant, which creates healthy people. In-furrow is really important, and most guys are doing a one- to two-pound-per-acre rate.

There are a couple of ways to look at quantification. You can look at the end product and make sure you have a certain set of numbers in the extract, or you can look at the compost and say, I've got all this here, and we'll assume we get it into the extract, because we know the efficiency of the machine. If I have a really good compost, I assume I'm getting this much. If I have a slightly lesser compost, I can speed up the auger — the speed of the extractor — and make a higher concentration to get the end product I'm looking for. So that one to two pounds really depends on the quality of the compost you're using.

Most guys are putting it down at five to ten gallons an acre, depending on the liquid system and the rates available to them. Again, stay as coarse as possible — 40 to 50 mesh is ideal — but it depends on your equipment. With an exact apply system or plate orifices you'd probably need to start at 60 to 80 mesh. Ideally, once you see the benefit of the extract, you adapt your equipment with variable rate orifices or micro tubing, so it can handle higher sediment loads. We don't expect every customer to do that up front, but once you see results, take the steps that let you get even better results.

Application: Foliar and the Digester Pass

Simeon: Then there's foliar application, which can go through a sprayer, a drone or a pivot irrigation system. That's about getting biology onto the leaf surface, and a lot of it runs down the plant into the soil. It's a really good time to put microbes and minerals out together — calcium, molybdenum and boron alongside your extract. The one thing you don't want to mix with biology is copper, so keep that separate as a bio-fungicide. A lot of guys are doing two or three foliar applications with nutrition and food to keep the plant healthy, and a healthy plant can resist tar spot, rusts, all the different fungal diseases that come through.

The final pass, after harvest, is a digester pass. Another goal in a regenerative system is taking away the vectors of disease. Corn stubble or wheat stubble can carry a lot of the season's disease, and if you don't digest it back into the soil, those diseases overwinter and come back worse next year. That's one reason you do crop rotation — to move those vectors around. But another way to improve it is the digester pass: number one, you get those nutrients back into the soil for next season, and number two, you decompose the home those diseases are living in.

A couple of other uses we've found really beneficial: you can run extract through drip irrigation for vegetables, or through a tree or vineyard irrigation system — we're in a vineyard right now, and they have an irrigation system you could run it through. The other place is your bulk compost turners, which usually have a way of watering. You can use extract to inoculate your bulk compost piles and make that compost even better, so when you apply it to your land you get a better end product with higher diversity. Liquefying the compost just lets you get it out so many more times over the course of a season than you would with a solid product.

Building Extract Into Passes You Already Make

Simeon: In a row crop setting that's seed treating, in-furrow, one or two foliar passes, and then the digester pass in the fall. In turf or ornamental — a permanent crop — you're aiming for an application every two to three weeks if you can get out there, just keeping the health of the plant going. We get really good results in turf. You increase the root mass, which increases regrowth, so you get better wearability — one of the biggest concerns for player safety. The field recovers faster, so you can host more games, and with a healthy plant you have less disease pressure and a really nice-looking field.

I'd rather you look for passes you're already making across your farm and see how to integrate extract into them. Say, I'm doing this nitrogen pass anyway — can I make extract with my nitrogen and use it more efficiently? The one thing you can't mix extracts with is insecticides, fungicides and herbicides. People do ask, and I definitely recommend against it, because those are designed to kill a lot of what you're trying to put out. If you do have to spray one, wait a couple of days or a rainfall before coming in with an extract. But it is really beneficial, once you've wiped the playing field clean, to bring the good guys back in and recolonize that space before the bad guys out-compete them. The whole point of all of this is to create balance in the ecosystem.

Right now, with a lot of our chemical agriculture, we've created a medium for holding the plant up, and then we have to spoon-feed it. You've created a vacuum where diseases and pests really thrive, because nothing is competing with them. We want to bring that competition back with the good guys. We're never going to eliminate fusarium, we're never going to eliminate these diseases, but we can keep them in check, because we have predators for them and competition for the food sources, and we're creating a healthy plant. A lot of these organisms change form and become beneficial in the right environment.

The Field House Soil Lab

Jesse: That's all very informative. If people want to learn more, or have you take a look at what they have going on — maybe they're thinking about getting an extractor and spooling up a system — this is probably a good time to talk about a new development, where you now have a place to remotely coach people, demonstrate equipment and show how things work. Tell us a bit about that.

Simeon: We've been building up our demo center, which we call the Field House Soil Lab. It's a space where people can show up physically for a demo, but we also have the virtual capability to do demos for people anywhere in the world. If you have questions about how to use an extractor, or which extractor fits your operation, we can walk through the different sizes and the options — water agitation, cleanability, the spray hose, what mesh size to use. We can answer questions about your vermicomposting system, our VermiFlow system, our hPack system, and the complete setup: the storage tank for the extract, the tank for the water, the filtration.

We don't really want to get into the consulting piece of building you a crop plan. For that we'd recommend visiting some of our dealers — AgriBio Systems Precision Bio out in Washington, Humankind Oregon out in Oregon — and you can go to our website for the full dealer list. What we want to make sure of is that you understand how the equipment works. If you have a machine and you have questions about calibrating it, calculating the concentration of your extract, or how to clean it properly, you can schedule that on our website or with your sales rep.

We're also hoping to use that space for more research: testing different storage mechanisms, different cover crops growing in vermicompost bins, turf trials, all kinds of things. If you have questions, reach out and let us know what they are, so we can keep testing and improving the equipment.

For people who've been following us the last four or five years, the machine has changed drastically based on customer feedback. We want to keep innovating and making new products, so if something doesn't fit or doesn't work well in your operation, tell us. Our goal is to provide equipment that makes biological applications effective and easy on the farm. That's where a lot of the engineering has gone — into cleanability and user friendliness. Minimal user interface with the machine, maximum outcome.