Add fungi to soil; don't subtract

The mushrooms would be grown on farms; they wouldn't be taken from the wild.

Obviously fungus like mushrooms are grown for food and other uses, but in terms of scaling up production for use as a building material, you have to think about how fungi work compared with plants.

A tree sprouts from a seed and gets energy from the sun to take CO2 from the air and re-arrange the molecules into cellulose. The roots use a bit of fertilizer (nitrogen, phosporous) from the soil, but overall photosynthesis and growth provides the energy.

Fungi, on the other hand, are consumers (not producers that make their own food from sunlight), so they consume dead material in the soil, which is a good thing, but growing more fungus requires adding more dead organic matter to the soil, which has limits in a way that photosynthesis doesn't.

Think of it this way: plants feed animals and both plants and animals die and decompose in the soil, feeding fungus who do the work of decomposing them. The fungi provide fertilizer for the plants to grow so they can feed the animals, but they are feeding their own food source, so to speak.

If you tried to make an operation out of cultivating and harvesting fungus, it would short-circuit the nutrient cycle in way that is even worse than harvesting animals for food and other materials. When you raise and slaughter animals, you are already taxing the soil and water supply by having to grow plants intensively to feed the animals.

If you wanted to grow fungus in the same way as animals, you'd have to feed them at a similar rate, i.e. because they are consumers and not producers.

So it makes more sense to use fungus to do their natural job, i.e. to manage soil nutrients and decompose organic material that dies and sediments into the ground. Tree roots find their way to nutritious soils and forge a symbiotic relationship with the fungi there. Then birds, squirrels, etc. consume the leaves, nuts/seeds, and fruits of trees and excrete their waste products to fertilize top soil for shallower-growing soil fauna, including fungi and bacteria, so that plants are supported as the base of the food chain.

Basically, plants & trees make food for animals and fungi are there to support plant/tree growth, so it is sensible to support healthy soil by letting fungi and bacteria stay in the soil for the most part and perform their natural soil-support jobs; not cultivate and harvest them for other uses.

Sorry to be so long-winded, but it is really important to understand soil fauna like fungi in the broader context of ecosystemic function.

Harvesting fungi is a bit like harvesting roots from a fruit tree; i.e. you could do it a little as long as you don't hurt the tree, but it wouldn't make sense to start growing and killing entire fruit trees for the roots, because that would undermine the purpose of a fruit tree, which is to stay alive and rooted so it can bear fruit.

It isn't about adding or subtracting. Fungus multiplies on its own.

Leave a piece of bread out on the counter, or just don't wash your feet for a couple of weeks, you will get fungus.

Life expands and grows to fill whatever space is available to it, as long as the necessary resources are present for it to 'multiply,' as you say.

Fungi use the space of soil, the sand and clay, to spread as mycelium (roots) and use whatever water and nutrients (detritus usually, I think) to live and excrete waste products that are used by tree and plant roots to support their growth above ground.

Plants and trees expand into the above-ground space, in other words, while fungi expand into the below-ground space together with plant and tree roots, and they support those roots along with other soil fauna, such as bacteria.

Animals are consumers that make space by eating their/our way through the other materials, including some fungi and other animals/consumers, but mostly plant and tree material, because that is the base source of energy/nutrients for all other life (consumers).

In other words, life doesn't just 'multiply' in any which way. There are food/nutrient chains that prevent organisms from undermining their own foundations and those of other organisms.

Expanding the uses of fungi to make building materials for boats or whatever on an economic scale would undermine the foundational role that fungi play in supporting healthy soil and thus plant/tree growth, which in turn supports the larger ecosystem(s).

It would be like making skyscrapers out of leather and animal bones. If you started trying to do that on a large scale, you would deplete all the agricultural resources used to feed the animals you slaughtered for building materials.

Resources have to be used sensibly and efficiently, or else problems result. The planet is not just a fountain of everything that magically produces as much of any raw material or other resource that you want to use for any purpose. Every resource has its own natural 'supply chain' processes that limit how it grows, how fast, etc.

Fungi grow by consuming detritus. Detritus comes from dying plants and animals. How much animal and plant material do you want to kill and feed to the fungi to make canoes instead of just using wood or fiberglass or some other material that is more plentiful and renewable at a faster rate with less harm to soil health?

When the fungus is in my basement or between my toes.... I kill it.

I understand your concern but there's no reason to think they'd be mining mycelium on a large scale from forests. I suspect they can find plenty of usable substrate from agricultural waste products. Once properly prepared and mixed with suitable amendments the substrate can be inoculated with spores and growth will ensue. It could all be done in a warehouse.

The economic nature of everything like this that gets published is to imply that it is scale-able and thus garner investor interest.

Of course whenever people do unsustainable/non-scaleable things at a local level, it doesn't destroy the planet or the future because they do; but if you look at the bigger picture, all the little unsustainable acts of land-clearing and fire and poaching, etc. etc. add up among a human population of, what is it now, seven or eight billion people?

So I am just pointing out here that fungi is not some kind of fountain of free biomass to build everyone a canoe without harming the environment. Fungi are consumers, like animals, that don't photosynthesize. We don't notice them because they mostly live underground and so they seem exotic and then it's easy to project all your magical-abundance beliefs onto them, but the reality is that healthy soil is an endangered species due to development and so economic proposals for using fungi for building materials is akin to wanting to hunt wildlife to make shoes, boats, or whatever.

True — healthy soil is a system and that system is precious.

But here's where we disagree. When fungal colonies fruit, their spores can be collected and used to start a new mycelium. It's not that different from collecting seeds from wild plants and germinating them in a garden. Once a healthy mycelium is established its spores can be used to propagate fungal colonies for industrial use without impacting any natural system. Hunting wildlife to make shoes wouldn't be practical but using the hides of domestic livestock doesn't damage wild populations. Similarly, growing fiber crops and establishing tree farms means that we can produce paper without depleting natural forests.

It's not that fungus (or livestock) can't repopulate after it's been harvested; it's that maintaining a population of consumers that reproduces and grows at a rate sufficient to supply humans at industrial scale requires similarly large quantities of process-inputs.

So just think about all the soy/grain/etc. that has to be grown to feed to livestock to maintain an industrial supply of beef for human consumption; and that would be similar for industrially cultivating fungus on a scale large enough to make boats, etc.

Do you know how tofu is made? It is just soy beans ground up and mixed with calcium. Basically it's just cooked soy. Compare that with feeding the soy to a cow so it can bear a calf, who then has to grow up big enough to slaughter and butcher.

Fungus is the same because it is a consumer and not a producer that photosynthesizes its own food from sunlight. What's more, it's not a primary consumer like a cow or other vegetarian animal, but rather a detritivore that feeds off debris from dead organisms.

Fungus should be left in the ground and the soil that is available to fungus to multiply and expand should be increased. The purpose of fungus and soil generally is not to use for building materials, or to cover with pavement and buildings, but to form a healthy-soil base for trees and plants to grow so that they can support the broader ecosystem, absorb/sequester carbon, clean air and water we eventually breathe and drink, etc.

Mushrooms pop up with fungal mycelium have such an abundance/surplus of nutrients that they have energy/material to reproduce. Mushrooms are the reproductive organs of the underground mycelium networks.

When you dig up mycelium, it's like digging up the roots of fruit trees and/or cutting back the canopy branches and limbs. The point of the roots and canopy are to grow the fruit, and it's the fruit you should be harvesting just as mushrooms are the fruit of the fungus to be harvested for food.

We use wood from trees as a building material, for paper/etc., but trees/forests should be maintained in a way that is sustainable and doesn't undermine the resource-base that maintains the forest and all its ecological functions. If you plant certain trees that grow fast so you can get more wood/paper over shorter time-spans, those trees consume more water and deplete ground-water recharge and/or surface water for other organisms. Other kinds of trees/forest protect and preserve soil moisture, groundwater flows, while also supporting broader ecosystem organisms/functions that contribute to the broader health of the land.

So whether you're dealing with forests/trees, animals, or fungus; you should be thinking about the broader ecosystem and how to carefully use biological products in a way that supports ecosystem health and long-term sustainability instead of undermining it or otherwise sowing seeds of long-term degeneracy.

I think harvesting fungus as a building material would cause long-term degeneracy of the soil and/or require large quantities of detritus to be harvested and fed to fungus on 'fungus-farms,' which would mean taking those soil resources away from other ecosystems and agricultural systems.

Generally it is just better to focus on plants and, ideally, sustainable tree products. Plant matter is the bottom of the food chain and thus the broad-base of the food/resource pyramid. Fungus and other soil fauna are the foundation upon which the plant-matter base of that pyramid is built. You don't want to undermine the pyramid by using its foundation as a building material.

Mushroom farm

Thanks for posting this pic. Do you happen to know what they feed the mushrooms?

According to Wikipeda

What are you referring to in the wiki article? The substrate? Is substrate the food for the fungus or the medium for the mycelium to spread through?

Either way, the point is that mushrooms need food like any other organism. They are not photosynthetic, so they have to consume other organism/detritus for energy and nutrients.

that is what I suspected so all you need to do to feed it is basically throw your garbage at it.

Sounds like a great gig - a good working farm would have plenty of crap to just toss in it -
When I was reading what was written on how fungi work, it makes logical sense to grow it on a farm = a great way to recycle stuff that a farmer would typically throw away.



Yep - crap - all the leftovers those things that you would normally toss out.

Right, but the question is whether it is better to turn waste into canoes and other building material or whether to use it to fertilize photosynthetic plants and trees that will absorb more carbon and harness solar energy to produce fruits/nuts/vegetables.


Yes, mushrooms are the fruit of the fungus; which is the logical thing to harvest from the organism.

Harvesting the mycelium to use like wood is wasteful because, unlike wood, mycelium doesn't photosynthesize.


Everything 'tossed out' goes somewhere and composts. Landfills also compost. It is better to manage waste in a more efficient way, by sorting trash into usable categories, such as by composting.

Growing mushrooms in compost is a good idea; just save the mycelium and keep feeding it to grow more mushrooms instead of turning it into 'canoe wood.'

Would you chop down a fruit/nut tree to use the wood to build a canoe? If not, why would you do so with mushroom mycelia?

What's more is that wild mycelia are symbiotically connected with the trees and other plant roots that are nourished by healthy soil. So even if those wild fungus aren't producing mushrooms for human consumption, they are supporting the trees and plants that grow with them.

It isn't a this or that proposition. Mycelium feeds on waste material. Fruits nuts and vegetables grown commercially feed, for the most part, on chemical fertilizers.

You're not seeing the big picture, probably because you just accept all the waste that's built into the economy instead of realizing that everything wasted is a lost opportunity for someone in need.

Fungal mycelium grow naturally in detritus/compost. When waste is transported to a mushroom farm, it requires fuel and time to transport it. If you just grow the mushrooms where the waste is generated, you don't need to transport it, except maybe by collecting it and bringing it to the place where the mushrooms are grown.

What's more, if you figure out that you can grow mushrooms in the soil with other crops/trees, you can use less or no chemical fertilizer because the fungus will manage the soil nutrients for you, as they do in a forest.

Have you ever heard of permaculture?

Yeah, how is that panning out?

How is what panning out? Do you mean how is permaculture panning out?