Jul 25, 2022
The 8 Most Popular Mushroom Cultivation Techniques For Commercial Growers & Amateur Mycologists
Written By: Justin Hyunjae Chung
Editor’s Note: This is an investigative article from Agritecture’s Agriculture Technologist on the core principles of and primary techniques for mushroom cultivation. Justin’s professional experience in the topic is supported by his Master’s in Biosystems Engineering from the University of Arizona’s Controlled Environment Agriculture Center (CEAC), where his thesis revolved around vertical farming and specialty mushroom cultivation. Learn more about mushroom cultivation in Justin’s last article.
Neither plant-like nor animal-like, mushrooms are ancient and non-photosynthetic organisms that belong to their own kingdom: Fungi.
In order to better understand mushroom cultivation as it relates to controlled environment agriculture (CEA), it is crucial to first gain a better understanding of the fungal kingdom and the fungal life cycle.
The primary role of fungi in the ecosystem is decomposition, or scavenging for dead and decaying organic matter and regenerating it back into organic life. In short, fungi are the “recyclers'' of the natural world.
The fungal life cycle starts when “spores” land on a suitable substrate and propagate to form “hyphae”. When two sexually compatible hyphae fuse together, they form dikaryotic (two nuclei) “mycelium,” which is the root-like structure of fungi that is responsible for secreting digestive enzymes externally to break down its substrate. After digesting the substrate and under the right environmental conditions, the mycelium forms “primordia” that eventually enlarges to become a fruiting body known as the “mushroom.” At full maturity, the mushroom caps “sporulate” and release spores back into the environment, thus allowing the cycle to repeat itself.
Mushroom cultivation is the art and science of harnessing mycelium, the root-like structure of fungi, to promote the growth of mushroom fruiting bodies.
Numerous techniques (referred in the mycology community as “TEK”s) are commonly used to achieve this desired outcome, ranging from trays, logs, bags, bottles, buckets, tubs, and more. There is no set regimen to growing mushrooms as it is the co-evolution/merger between humans and fungi which manifests itself in many unique ways.
This said, the core principles remain the same. The mushroom cultivator is harnessing the growth of mycelium, the workhorse of the fungal organism, by feeding it the right amount of nutrients with the right timing, akin to a surfer riding a wave as it crests.
After mycelium (agar tissue, liquid culture, grain spawn) is ‘inoculated’ onto a pasteurized or sterile substrate, the mycelium ‘colonizes’ the substrate by secreting digestive enzymes to break down the lignin, cellulose, and hemicellulose of the substrate. After full colonization, the mycelium produces ‘pins’ that eventually become mushrooms under the right conditions.
The fruiting conditions should mimic how mushrooms develop in nature, which is the right mixture of temperature, humidity, CO2, airflow, and lighting.
In the growing environment, the “invisible enemy” is contamination, particularly in the early stages of growth, as unwanted competition from airborne spores or bacteria can compete for the same resources. Contamination management is analogous to integrated pest management (IPM) for vertical farms and greenhouses.
The main operational tasks for growers are substrate preparation, pasteurization / sterilization, sterile transfers / inoculations, fruiting, harvesting, disposal, and cleaning. Each mushroom cultivator will have their own equipment to accomplish these tasks, while also coming up with strategies for energy, water, and waste management.
Mushrooms, and more broadly Fungi, serve as the nexus point for climate-adaptation, regeneration, and resilience.
My own version of a circular agricultural system would include mushroom cultivation at the center, branching out to insect production, aquaculture, animal feed, plants, and other forms of organic waste management.
For long duration manned missions to the Moon and Mars, my colleague Sean Gellenbeck’s research paper titled Mushrooms on Mars highlights the value of fungi in Bioregenerative Life Support Systems (BLSS). Perhaps fungi have the ability to aid humanity in terraforming Mars in mysterious ways.
As humanity enters into a period of resource depletion and buildup of toxic waste, allying with the fungal kingdom could be our solution to achieve a new equilibrium within our own spaceship - Earth.