Dan talks about no till (minimum till) harvesting techniques and living mulch trails.
Rushka and Emma discuss drought problems and planting mistakes in South Africa. In passing Emma mentions watering her trees with Comfrey tea. Comfrey is high in potassium and that helps plant stomata regulate moisture, and encourages fungal colonisation. Go Comfrey. You can generally find potassium in skins/rinds of fruits too.
Stomata open vs closed and the role of potassium ions in closing:
I don’t have any Comfrey here, however to make the most of scarce water when it’s dry here in Australia I’m trying organic fertigation rather than simply watering, especially for younger plants. I’ll make up an organic soup if it hasn’t rained for a couple of weeks or we’re expecting a long stretch of hot weather, and apply that and not water unless plants are still drooping in the mornings before it heats up.
A study I read showed that microbes start to go dormant and die after 2-3 weeks of drought in some climates, and when that happens some of their soil aggregate glues break down and begin to leach nutrients when you do water or it intermittently does rain. I recently learned that the rate of soil aggregate breakdown or growth is exponential too, so keeping microbes happy in the goldilocks zone is important. Mulch and feed them!
My process is to take soft green cuttings from plants/weeds that are growing well and chop or blend it finely into a bucket as this chopping adds useful surface area and edge and aids the breakdown and dissolving of nutrients. Herbs can be used for their high nutrient density, however be warned that their oils could impede fungal growth.
Then I add a couple of tablespoons of the least processed sugar I have, ideally that’s a piece of crushed fruit or a syrup. Not all sugars are equal. Compare Maple and Panela(Rapadura/Unprocessed Jaggery/Cane sugar) with centrifugally spun raw and refined sugars that are mostly carbon.
I add to that 1 part aged urine and 5 parts water and add a handful of good moist topsoil for indigenous microbes or compost. Optionally, if you have some moist crumbly wood that is covered in fungi, add that too, otherwise ground up rough bark can work, as this can help add fungi and nucleation points I’ll get to below. The fruit adds sugar and potassium (for fungi and plant stomata that control plant moisture), and the urine adds nitrogen which helps speed the breakdown of carbon compounds in the plant material, while both also add soluble compounds. Stir well with forward and sudden reversing motions for 5 minutes and then steep for up to 6-8 hours. The mixing is very important. Ideally the mixing container is larger than the amount you want so you can easily stir at speed and change direction to mix it well while not making a mess. Get out your drill and make a wire stirrer, or kitchen beater if you’re lazy. 🙂 You want to really froth the water with forward and reverse action to help mix and aerate it like your washing machine might. All the particles in the water will end up covered in tiny bubbles that form nucleation points that way, and become feeding stations with air, nutrients and water at their boundaries that should last long enough to stay mostly aerated for our needs.
You should get something like these carbon dioxide bubbles forming in solution around a finger, but in our case those bubbles would be on all the particles suspended in the water.
Studies I’ve read show it takes about 6-8 hours for most labile minerals to dissolve so I don’t bother going much longer than that. And while this process will culture microbes too, that isn’t the main goal here.
If I have charcoal I’ll grind that into a powder and add that to my soup too, as it helps aerate with lots of pores, and hold onto the nutrients in the soil and partially dissolves to feed soil organisms. Porous material that will partially float like crushed expanded clay balls are another good addition as they hold air and nutrients in the water column. Eggshells, oyster shell, limestone, etc, baked, crushed, then soaked in vinegar is also optional for calcium. Like us, calcium is used in the skeleton of plants. A source of silica is also important as plants take it up during drought in place of carbon. The porous diatomaceous earth made from tiny diatoms, a type of phytoplankton, is one source. Oats, millet, barley, potatoes, banana peel and bran cereal are others.
I either make my soup in the morning and apply at night, or at night for steeping overnight and applying in the morning. That’s it. You can test with a pH and Electrical conductivity meter to see how well you did, or just apply it and see what results you get.
The simple version is simply aged urine, water and sugar, this stimulates carbon priming from mulch materials accelerating their breakdown.
The more complex version is as complex as you want to make it.
It should be noted that some minerals require acidic environments to dissolve, and fermenting for long periods can help, so it all depends on your goal here. Should you ferment for longer periods, ensure that none of the material you add is high in heavy metals.
It’s worth noting that fungi are drunks. They exude alcohols and acids to break down matter. They also move water along their hyphae network at up to 75mm (3″) a day and can share it among friends. This is why they’re so valuable to drought areas and should be encouraged.
- Enough soft chopped greens to fill half a container, or less if using plant-based meal (ground up plant material)
- 1 part fruit (2 tablespoons of sugar or syrup)
- 1 part handful topsoil (or compost)
- 1 part aged urine (at least 1 month at room temperature)
- 5 parts rain water (non-chlorinated water)
- 1 piece of fungi covered crumbling wood (optional)
- Micronised charcoal (optional)
- Crushed clay balls as used in hydroponics (optional) (Or cook come clay and flour with fire to 200 Celsius then crush)
- Baked crushed eggshells soaked in vinegar (optional)
- Bonsai medium like crushed bark as used in potting mixes (optional)
- Silica/Crushed Diatomaceous Earth (optional)
Bonus: Why use mycelium covered crumbling wood? Water holding and Liquid Mycelium!
Three to six times more microbial biomass carbon and nitrogen depending on soil type.
These results provide evidence that carbon (C) inputs from frequent cover cropping are the primary driver of changes in the soil food web and soil health in high-input, tillage-intensive organic vegetable production systems.
Fresh is best.
Due to interrupted news reading thanks to Feedly (my news reader) bugs, today I’m thinking about compost and mulch.
What makes a good compost? What makes a good mulch? Where do we delineate the two? Today I want to start with the first question.
In my earlier post on the Carbon & Nitrogen Priming of Organic Matter I highlight the desire for organic matter with a C:N below 50:1 if we want to be priming our soils and building soil carbon. Composting is one way to do that with a general target of 30:1, but in the process of creating compost are we maximising the potential of the materials used to create it and the microbiology that comes along for the ride? Read some of my thoughts about that in Hot Compost, Cold Compost? Not Compost. [Rant]
We’ve also seen in How much Soil Organic Carbon is best? that there’s a tipping point for fungally dominated soils, and so it only makes sense to want to prioritise fungi.
I recently watched Charles Dowding turning a tonne of compost to get more air into his pile. I asked him in the comments what he’s doing differently this year and he replied that he’s trying to add more wood shreddings to increase the fungal part, and manage the moisture content with roofing. Both excellent goals.
The turning however is what got me thinking. I know from previous research on farmland that tilling soils reduces mycorrhizal fungi by half in the first month, and also that for every subsequent month left fallow those remaining fungi halve again. Is it the same for compost? How does the heat affect them and other organisms? Their spores are said to be invincible by some, but are they all?
That leads to the question of is turning compost desirable at all for fungally dominated compost? Is the heat in compost even desireable?
Most composting methods like Charles uses, turn compost, effectively tilling it. Most compost is also left fallow, without a living host for mycorrhizal fungi and their symbiotic relationship.
There are composting methods such as the Johnson Su Bioreactor and other no turn composting methods that solve the first problem, but I’m yet to see a plant that can survive the temperatures composting creates to host those mycorrhizal fungi. Perhaps at the edges they do? But for how long as the nitrogen and carbon declines as organisms take the labile carbon up?
To solve this many people later add mycorrhizal fungi inoculates, however testing has shown nearly all don’t actually contain what they’re said to when you receive them, and they likely contain all kinds of other foreign organisms.
Others collect Indigenous Micro Organisms (IMO) from local natural settings and culture those, or create teas and add them later. However I’m yet to see any that culture them in the presence of host plants. And we know from laboratory culture techniques that very few species can be cultured in artificial environments like petri dishes and various agars.
How vital then are host plants for culturing mycorrhizal fungi and other symbionts?
Is it a non-issue or something we’ve overlooked in creating symbiont dominated soil amendments?
Should the Johnson Su Bioreactor style design be planted out to look more like the drum planter with the type of plants you plan to grow?
Here’s a design I’ve just thought up. Below is the Permi Flix Bioreactor top-down view, a modification of the Johnson Su. Inoculated with multiple IMO soil sections around the perimeter, with aeration pipes in the middle. With a watering system just like the Johnson Su. The idea is that you cull and select for plants and microbes that produce the best results planted in the different IMOs around the outside edge, as highlighted by the coloured sections. I’m calling it the game of life. It could also be done with multiple composters and the same material, each with their own IMO mix.
Wait a week before planting?
Or just mulch, inoculate, plant and never disturb?
Just a thought on a Feedly-deprived day.
Hot Compost => Compost
Cold Compost => Biodegradation
Vermicompost => Vermicasting? But they’re not just castings => Organic Matter?
In my world, composting requires a certain temperature for it to be called compost. If it’s not hot it’s not compost, then it’s biodegradation. Composting is just biodegradation at a certain temperature for a certain amount of time, usually with the aim of killing off “pathogens”. Gah. because all pathogens don’t like it hot right? Ugh. It’s like the anaerobic vs aerobic pathogen argument, don’t get me started on that.
Vermi and compost make no sense together either, neither does cold and compost, yet everyone is doing it and sucking me in with their hot compost beliefs.
Biodegradation can happen at cold or hot temperatures.
Composting kills off microbes that don’t like it hot, that’s a given. How is that good for microbial diversity and plants that grow at ambient and not hot temperatures? Because you kill off some plant pathogens at those temperatures? At what cost?
Sure compost breaks down more things and faster, however people seem to place it on some pedestal. All that heat is just energy going up as hot air! Composting sends a lot of the matter and energy into the atmosphere. It also requires a heaped pile to keep the temperature high, and a concentration of materials is a great way to create pollution in the form of leachates in the one place too, especially when rained on. Raking or collecting materials for a pile might give you a nice clean garden but it also means less ground cover that could be providing multiple benefits to the soil too! But it’s neat, it’s tidy! It’s organised and sanitised! It doesn’t attract creepy crawlies.
Compost, what is it good for? Absolutely some things.
But not others.
I’d rather most materials were mulched and left as ground cover to biodegrade at ambient temperatures where possible. Whether that be plant litter chopped and dropped by plant or animal, or a hole dug and organic material buried. Organic litter feeds soil, it helps manage temperature, moisture and microbes. It’s a house and a job for the homeless all in one, the best kind of help those on the fringe can get with services like water to boot!
Mulch everything. Vermiculture, Ferment, Anaerobically Respire, Compost or Pyrolyse what doesn’t biodegrade at ambient temperatures.
Composting should be one of the last resorts, not the first.
Growing and feeding living mulch should be the first.
Maximising photosynthesis in order to create more mulch to maximise photosynthesis!
Feedback loops. The Green, and Red, and Purple, and Psychedelic Rainbow.
If it’s brown, thumbs down.
If it’s bare, *death stare*
Down with compost piles!
And spread them around.
Let them slowly feed and nurture plants and soil, not themselves.
Formation of soil organic matter via biochemical and physical pathways of litter mass loss : Nature Geoscience : Nature Research http://www.nature.com/ngeo/journal/v8/n10/full/ngeo2520.html
All soils are different. However No dig and diverse cover crops that keep fungi fed and alive are definitely the preferred method as the less the soil disturbance, the more the plants photosynthesise and feed the undisturbed soil microbes like fungi that then build soil carbon and structure.
However for soils with poor structure, low soil carbon, and hard clay pan compaction layers, then subsoil manuring can be a faster option as it gets the food to microbes where it’s most needed. Ideally with minimal inter-layer disturbance, and optionally then with a layer of weed suppressing material, mulching and planting through. You have to always remember to plant out bare mulch and soil however, otherwise mycorrhizal fungi that require plant hosts will die off. About half of mycorrhizae also die within the first month of tilling and a further half every subsequent month soil is left fallow.
When subsoil manuring you have to make sure there is enough soil moisture for the microbes to break down that subsoil manure and integrate it too. Studies suggest materials with a C:N of less than 25:1 appear to be the best to feed those subsoil microbes. Basically anything green, eg. grass, fresh leaves that aren’t allelopathic, or alternatively compost or animal manures if you want a higher bacterial to fungi ratio that the high phosphorus, particularly in animal manures encourages (normally you don’t). Mulch helps maintain moisture, and the mulch should ideally be below a C:N of 100:1 as this speeds the building of soil carbon. Those are mulch materials like leaf mold, straw, shredded newspaper, and ramial (branch) chipped wood, ideally all mixed together for diversity. Those materials that are high in potassium and low in phosphorus are also likely to encourage fungi.
Digging without amending however is generally a bad idea as it destroys soil structure, and can lead to soils drying out where those cracks form, which then causes the soil mucilage (glues) and microbial exudate to dry out and leach. Leaving sand, silt, and clay ready to combine and compact with one another.