Root Exudates vs. Sprayed Teas

I realize that I am setting up an either/or false dichotomy from the outset, but my question is: which is more beneficial to long-term soil health, feeding the micro-herd food web and enhancing plant growth? If you had to choose one, would it be putting your efforts into brewing and spraying compost tea (or any other variation of teas people make -- comfrey, etc.), or would it be focusing your efforts on planting a rich diversity of cover crops, companion plants and plant guilds, so as to pump root exudates into the soil?

Foliar spray teas are applied directly to the plants, or can be feed into the root systems of plants by watering with them. It requires time and effort to manufacture them, filter them, spray them, but the benefits seem to be quite immediate, and the long-term impact upon soil health is also observable over time.

Root exudates also provide extensive benefits to soil health, but their impact isn't seen as quickly. It may take a year or two of cover-cropping, no-till planting, as well as chopping and dropping before you see better soil aggregation and plant response. Unless you are mindful about closely observing, often you can't really tell that much is happening below the surface—the soil food web and bacterial community does its work silently and invisibly. The roots are buried in the soil, so it's impossible to see the bacteria and fungi being feed by the sugars being secreted into the root zone.

So -- choose one. (Recognizing that many of you put a great deal of effort into both). If you had to give your energy to one technique to improve your garden/food forest/orchard, what would it be and why?

For me, making teas and other things to spray on plants to make them grow is just like buying chemicals and using them. Both are artificial means to get plants to grow.

I used to make teas and other things for enhancing plant growth/ health, this was when I was a commercial nurseryman working for my mother.
Now it just takes to much time and effort to go through the motions, today I simply use the compost the plants provide after harvest is completed (chop and drop).
The only "additives" I use now are to increase bacterial and fungal growth, density in the soil, even then, these items come from our land so I suppose they are not truly additives but rather redistributions of what is already here, just not exactly where I need them.

Now-a-days I try to not think like the scientist I became in the white eyes world of colleges and their degrees.
Now I work with mother earth and use her methods for most all things (Human poop being one area I can't duplicate natures ways and so have to use "the standard methods" of dealing with this item).
I grow cover crops (trying to keep to those that already can be found in my farms area rather than import seeds to do the same job the local plants can do seems like a waste of money.
I do plan on growing some items like comfrey, that are not localized but they will be sequestered so as to keep them from escaping to the wild, most of this sort of plant importing is for medicinal uses only.

I would have to put myself into the category of soil health builder over fertilizer maker/ user.

Since I want to be growing a diversity of plants anyway, and like to avoid extra work, I'm going with a diversity of plants, not special preparations.

I would say that it is going to depend a lot on your land. If the land is terribly degraded to the point that soil is lifeless dirt then some judicious use of compost teas might be worth it to help kick-start the soil life that supports the plant life.

Once there's even moderate plant cover I feel like I get more returns for my efforts from just focusing on increasing plant diversity and doing regular chop-and-drop routine.

Both techniques are just tools in the permaculture toolbox and like tools they're great when used for their right purpose, silly and wasteful when used for the wrong thing.

I'll weigh in on my own question.

I messed around with making compost tea and comfrey tea for a couple of years. It's a LOT of work. My totally non-scientific side-by-side trials didn't really show that much benefit (if any). Initially, I thought that using the compost tea as a foliar spray seemed to make the plants perk up, but after a few days, I couldn't tell the difference. I had a couple of rows of corn, one of which was sprayed weekly for a month, and the other not sprayed at all. Upon harvest, the sprayed corn didn't yield any larger ears than the non-sprayed. I would spray my already healthy looking trees --- and if it helped, it wasn't as if they suddenly jumped up in a way that was significant.

I'm not saying that compost tea spraying isn't effective, but in my experience, I just didn't see any discernible difference.

As for using compost tea to stimulate soil microbial activity, that makes much more sense. However, since I deep mulch throughout the food-forest with wood chips (Eden method), every rain event is, in essence, a compost tea dousing for the soil. After laying a new layer of wood chips down for the past 16 years, there is so much microbial and fungal activity in the soil that any additional boost given by the compost tea is essentially not necessary.

However, I've become a huge cover crop fan in this same time period. In the summer, every empty space is planted with veggies. It's tough to find enough space to plant everything that I start in pots. All those plants are putting out exudates. Once October and November come along, most of those summer crops have been harvested, and a thick cover crop with 10 or more species goes into the ground. I have a hillside that is difficult to do very much with because it's pretty steep, but I've got a 15 fruit trees back there (avocados, peaches, figs, asian pears, nectarines, cherries). Between the cover crops and the sweet potatoes that volunteer back there, the bio mass is very significant, and there is a living root pumping exudates into the soil from November through May. Then, throughout the summer and fall, vining crops are allowed to run wild back there, and additional wood chips are laid down in any open space.

Between the chop and drop bio-mass produced by the winter cover crops (which regularly grow 4 or 5 feet high), the wood chips that I lay down by the ton/truck load, and the compost that is generated for use in potting soil and to prep holes where things are being planted, the entire third-acre is basically covered with composting plant material. The roots of hundreds of plants are busy building soil life. I don't feel the need to go to all the work making compost tea any more.

Marco Banks wrote:I realize that I am setting up an either/or false dichotomy from the outset, but my question is: which is more beneficial to long-term soil health, feeding the micro-herd food web and enhancing plant growth?  If you had to choose one, would it be putting your efforts into brewing and spraying compost tea (or any other variation of teas people make -- comfrey, etc.), or would it be focusing your efforts on planting a rich diversity of cover crops, companion plants and plant guilds, so as to pump root exudates into the soil?

Precisely: Starting from a false dichotomy is bound to lead you astray. Why not do both? Nothing is antithetical between the two, and both are beneficial. Planting clover in the orchard to improve the soil is a good idea because it benefits my bees as well but the isolated trees growing in the orchard can get quite a boost from a foliar spray of comfrey tea. I'm not sure what useful knowledge is gained by opposing 2 methods that can be used in tandem. Both are resources and folks will use what they have, can till under or spray. If you want to *measure* the positives of each, you would have to compare the 2 in similar settings and similar crops, similar soils and climate. That might be left to scientists and labs. Both enhance soil health, both feed the micro-herd food web, both are a plus to the plants that will be grown in the field.
Another way to look at it is the economic aspect of both methods: Clover is an expensive seed but should 'last' a few years. I bought 30 comfrey roots and that was a great investment: I have been pulling from these plants for 2 years now, and they can make *A LOT*  of comfrey tea, which can be poured, diluted, over many other plants in the garden and the orchard.
I would say that I have a 'preference' for the comfrey tea because past the initial expense of those 30 plants, it has served me very well, does not add weeds to my plantings and really gives a big boost to every plant it is added to. But when it comes to *justifying* my preference, there are too many variables for me to say that it is the best thing for everyone or even for most folks. Annuals in the garden will fare really well with comfrey tea. This year, I think I will divide these 3 yr old plants and should have more than enough for my plantings, perhaps also for my chickens once in a while. I wish comfrey was deer resistant so I could put it a little bit everywhere. I will probably double the size of my garden so I can put more comfrey in it, grow more things. It is more of a personal convenience and the results are great with either method of soil improvement.

I have only chopped and dropped.
Even my attempts to establish cover crops have been largely thwarted,between existing "weeds" and in the last few years, chickens!
With only so much time, I often must chose of how  to feed my land.
Ive been looking into teas as a way to feed/treat sick plants, inoculate biochar,and  treat/feed livestock.
It seems like a way to push nutrients,kind of like a smoothy.
Id hate to live on smoothies alone, but especually if Im ailing,they really seem to help me.
My best soil building has come from strait carbon.
Leaves and woodchips,with little nitrogen,still seem to become great soil.
Chopping down a stand of sunchokes takes fewer resources than crafting a foiler friendly tea.

If I can get "cover crops" of nitrogen fixing shrubs to grow,they can provide exudates,nitrogen and carbon.
Oh, and chicken feed.
Prairie Mimosa, Silver berry, Goumi, etc, all of these hold more appeal than fiddling with funky water.
The funk is another issue. My wife takes issue with funky stuff,inside the house or outside.
The chickens have saved my composting efforts, since they cycle the waste faster than it can get funky, turning the pile, and eating the maggots that otherwise would bring their own funk.

If I find time, I will be playing with teas, but just growing plants seems more rewarding.
Hell, it just happens if I get out of the way,and later Iget to reap those box elder, mulberry,and rose of sharon, giving me kindling,carbon and nitrogen from root dieback, tree hay, and marshmallow sticks.

Side note, feed the green tree hay to the bunnies and they will strip the bark, leaving nicely seasoned kindling.

I am going to agree with Cecile.

I don't see an either/or.

I started to make compost tea because I had $400 worth of plants that were dying and I didn't want to spray with toxic synthetic chemicals.

Learning how to make better compost tea was part of the process.  Once you know how to make it, it's not very hard.  

I have a suburban garden, not a farm, so that may make a difference.

Every year, I've been adding leaves from trees that aren't related to mine in the fall and wood chips to my soil.

I've also cultivated an intentionally diverse yard and I chop and toss- so the cuttings go under other, non-related trees/plants.

If you don't have any mulch in your yard, the compost tea is not nearly as effective. In my opinion, it is most efficient as a seed to put on other organic matter, which is what you're doing with cover crops or adding organic material.

I didn't used to make horsetail tea.  Then I started to get horsetails and I've been grooving on them. My wife hates them, but I can make that tea now.  I could make comfrey tea, but I just chop and toss with it.

The longer I've been doing all of these, the less I need to make compost, etc teas.  Mostly it's now for plants that wouldn't naturally grow in my climate, but that I like to eat, like peaches, quince and serviceberry.

The idea with permaculture is that it gets easier over time, and you're mostly just harvesting, performing experiments,  and grooving out. That's what I got.

John S
PDX OR

I think it makes sense to START with feeding and multiplying the beneficial soil microorganisms with compost teas ( a term which I find too crude and imprecise).

Macroorganisms like plants and people owe a great deal of their health and wellbeing to the vast communities of microbes on and in them.

You don't want to just throw down some NPK or live on a diet of McDonald's (for the calories) and vitamin supplements (for the nutrients). You also want to make sure your body (or plants) can take in the nutrients.

My understanding of the mineral supply chain is that all minerals originated in the interior of the earth, which is why some people recommend volcanic rock dust to remineralize their soils, with products like Azomite.

However, not all mineral are immediately plant available, and need soil organisms to MAKE them available.

Soil organisms eat the minerals, and each other's bodily wastes, and each other's living or dead bodies.

Again, correct me if I'm wrong, but if on the way a plant nearby has a deficiency of, say, magnesium, it will put out root exudates which attracts the right soil organisms which process magnesium into a plant-available form.

Continuing down the mineral supply chain, eventually all minerals will end up in our waterways and get flushed out into the ocean, which is why other people recommend remineralizing their soils with diluted seawater or seaweeds. With seawater, the minerals are already water soluble, and seawater contains everything anyway, so its inclusion in nutrient sprays and/or soil drenches makes sense.

If the nutrients simply aren't THERE, they won't be conjured up by plants. If the nutrients are there but not plant-available, it will try to attract the right microorganisms to make them available. Therefore, again, it makes sense to me to first make sure the soil is well-populated with MICROorganisms, THEN make sure it is well-populated with MACROorganisms.

Hi Marco.

I like to think of extracts as a tool to boost soil life in a condition where it is lacking. If you have really bumping soil life, and if you are managing moisture conditions as you are so that it sustains a thriving population, I wouldn't see the need.

I think that it's important to make sure that, as you are doing, fungi in the system are encouraged to thrive by providing them appropriate conditions, and your woody mulch should be doing just that. They are, after all, what's going to regulate nutrient levels in the soil, right?

I think the only time I would use extracts on healthy soil is if I am adding a lot of biomass, where I want to encourage fungal colonisation.

The right tool for the right task at the right time seems the best approach.

-CK

I think we're mostly talking along the same lines.  When I bought my house, it was all grass with compressed clay, "fertilized" with toxic sprays every year.   We want to go from there to a permaculture paradise.  How?
We've got to get the whole team playing. If it was baseball, and you just didn't have a right fielder, everyone on the other team (pests and diseases) would hit a lazy fly ball to right and they'd get a home run every time. By adding organic material and cover crop/chop and drop/toss as well as teas, we have the food, and the nutrition for the complete microbiology team.  Elaine Ingham mentions that every soil has the right elements, we just have to have the balanced biology to let each part do its job.  If we don't put in too much phosphorus, the mycorrhizal and other fungi if we get them started with foods like wood chips and organic material.  Then the trees and other perennials can access water, minerals and other nutrients that were previously unavailable.  Diversity of plant life will lead to diversity of microbiology in the soil, so, as Rachel Carson says, "the balance of nature" will create nutrition for plants and for us.  Weeds come because they are trying to heal the soil.  Many are edible and medicinal. If we can gently manage this process through a balanced way, the ecosystem will be healed in a way that heals the soil that heals the plants that heal us.
John S
PDX OR

It seems like there is general agreement on the issue. If your starting with some seriously depleted soil and want to jump start your soil biome then teas or extracts are a great way to start. Once you have done the work of healing your space and have built up biomass and have a good rotation going then it is just an unnecessary step. Other factors might be the size of your space and how much fun you have making and applying teas. Generally though, teas/extracts seem best suited for jump starting an imbalanced system, developing diverse and healthy plant communities is definitely the more efficient way to maintain the soil in the long term.

I notice that the only variable being mentioned is the soil. There must be many other variables we could find that come into it, if we look. Air humidity and climate come to mind. Where I live, the summers are very dry. In nature, the soil surface is not damp enough for decomposition, and when people water enough to imitate the nutrient cycling of moister regions, they often get problems with symphylans and other root-eating organisms that are normally controlled by dryness. I find the teas and brews to be a big help during the summer.

I think perhaps the regular and ongoing use of extracts might do well in cases of really intensively managed gardens in urban and suburban areas. If one's soil biology is constantly under siege, I could see using them on an ongoing basis, especially if the conditions make it difficult to get mycorhizzae going or keep them healthy.

-CK

I have one standard raised bed, 6x12'. Two enclosed"beds" 4x6' each, that house very large containers. The containers are, obviously, confined spaces and the plants rely on me for nutrients, but the raised bed is on the ground so the plant roots can grow to China if they want. We have 2-3 seasons here so the soil definitely needs a boost from me. Soooo...when I started all this I used everything because I didn't know any better. Foliar tea, watered-in tea, organic purchased ($$$) granular fertilizer, oh hell, I'm sure there's more. The yield was great with some crops, so-so with some, abysmal with others. Too much work!! This season I amended the containers with compost and a more vigorous digging-in of granular fertilizer and compost on the big bed. That's a ridiculous amount of work I don't ever want to do again...but I didn't stay on top of the grass growing up from the ground so I had to pull it out and amended the soil then. I've covered 3/4's of the bed with cardboard to block out the grass since I'm just using a small patch for greens right now. I feel like I have a pretty good system there now. But what I'm doing this season is growing only varieties that thrive in Florida. All are new - tomatoes, peppers, salad greens, and new for me are huckleberry, okra (ewww, but maybe I'll like it), and Malabar spinach which I'm loving. Everything is thriving. Will I have to foliar feed? If I do, that plant is out. Tomatoes have really done well in the containers so it'll be fun to see how the new varieties compare. So foliar/watered-in tea is out, but I'll keep adding to the soil each season. My compost is comprised of chicken manure complete with shavings, rotted tree limbs from the woods, kitchen scraps, old soil, and whatever else I can find. The stuff is amazing, so I don't bother myself with ratios of the "right" material. I get great ideas here, so thanks to all.

The consensus seems to be
if you are sick take your medicine - teas and extracts.
if you just need to be healthier eat a good diet and get your exercise - living roots in the ground and plant debris on the surface.  

John Saltveit wrote:  Diversity of plant life will lead to diversity of microbiology in the soil, so, as Rachel Carson says, "the balance of nature" will create nutrition for plants and for us.  Weeds come because they are trying to heal the soil.  Many are edible and medicinal. If we can gently manage this process through a balanced way, the ecosystem will be healed in a way that heals the soil that heals the plants that heal us.
John S
PDX OR

This seems to be the opposite of what I was saying, a veritable chicken/egg scenario.

My point was, balance and feed the soil, and the plants will take care of themselves. However, you seem to be saying to add a diversity of plants and the soil will take care of itself.

I'd love further clarification. Perhaps we are both right?

Chad Sentman wrote:

John Saltveit wrote:  Diversity of plant life will lead to diversity of microbiology in the soil, so, as Rachel Carson says, "the balance of nature" will create nutrition for plants and for us.  Weeds come because they are trying to heal the soil.  Many are edible and medicinal. If we can gently manage this process through a balanced way, the ecosystem will be healed in a way that heals the soil that heals the plants that heal us.
John S
PDX OR

This seems to be the opposite of what I was saying, a veritable chicken/egg scenario.

My point was, balance and feed the soil, and the plants will take care of themselves. However, you seem to be saying to add a diversity of plants and the soil will take care of itself.

I'd love further clarification. Perhaps we are both right?

To best heal the earth mother we have to do a multi-tiered approach.
We must put into the soil the most complete microbiome we can so the soil life has the diversity needed so when plants use their exudates to call for nutrients, those processor organisms are present in the soil.
We must also grow a diversity of plants so the number of different exudates coming from a diverse plant community of roots in the soil activate as many different micro organisms as possible to keep all the life operating well.
So we first spray our compost teas to increase microbiodiversity then we plant lots of different species of plants to get a plant diversity, together these loosen tight soil, add humus and the whole system works to create soil that infiltrates water, holds onto nutrients and grows healthy plants which feed us.
We then recycle the left over parts of the plants so those nutrients held within the plants is put back into the soil so the whole process continues.

Redhawk