Tree Mushroom Production
for City Farmers
By Su Decheng
Su Decheng, a scientist, worked at Valley Mushroom Company in Nova Scotia.
Excellent new information can be found here: BC Mushrooms - Non-Timber Forest Products (NTFP)"The pine mushroom (Tricholoma magnivelare), is by far the most valuable commercially harvested mushroom (in BC). Other valuable edible mushrooms are the chanterelles, morels, lobsters, boletes, cauliflowers and hedgehogs."
The mushrooms Su Decheng grows are shiitake (Lentinus edodes), maitake (Grifota frondosa), enokitake (Flammulina velutipes), oyster mushroom (Pleurotus osteas), lion's mane mushroom (Hericium erinaceus), and Ling-zhi (Ganoderma lucidum). These mushrooms are able to decompose polymer, cellulose , lignum, and hemicellulose from agricultural and forest residues and at the same time produce a valuable mushroom crop. The substrate, once the mushrooms have been harvested, consists of mushroom mycelia and is an excellent fertilizer.
Su Decheng describes his background and work
I was born in a mountainous area of Fujian province, in the south-east of China where I lived my first 16 years in poverty. I went to Xiamen University, and spent 4 years majoring in biology with the idea that one day I could help my countrymen get out of poverty.
When I found that my undergraduate knowledge was not enough to fulfil my ambition, I took another 3 years at Beijing Agricultural University, (The University is now renamed the Agricultural University of China), and completed a masters program studying the molecular genetics of fungi, graduating in 1987. Since then I have been working as Associate Professor of Mushroom Science in the Land and Environment Department of Fujian Agricultural University.
On receiving my Master of Agriculture (Microbiology) degree at Beijing Agricultural University in Beijing, in 1987, my friend took me out to a restaurant to celebrate and ordered "monkey head" from the menu. I wasn't happy when the waitress brought an unusual vegetable dish named "Here is the Monkey Head". On seeing my expression my friend explained to me that monkey head is the name of a mushroom. This surprised me because I had graduated in microbiology, and yet I knew nothing about this variety. I decided to study mushroom science and for the past 9 years, my work has involved research on the technology of growing mushrooms.
Monkey head also called bear's head or lion's mane, is one of a group of mushrooms known as tree mushrooms. Tree mushrooms have been grown for hundreds of years in China and Japan. They are different from white mushrooms (button mushrooms) in that they grow in nature on fallen logs in the forest.
These mushrooms have a pungent, woodsy flavour, and have good nutritional value. They provide high levels of protein, minor elements, vitamins, amino acids, and have low fat content and few calories. Most of them have natural anti-viral and immunity-boosting properties that are used to fight viruses, lower cholesterol and regulate blood pressure. Besides monkey head, there are maitake or hen sitting in the wood, shiitake, oyster mushroom, phoenix-tail mushroom, ling-zhi or reddish, enokitake or golden mushroom.
Although they grow on wooden logs, we can cultivate them on a variety of substrates. Inedible biomass such as sawdust, crop stalks and other agricultural and forest waste can be used to grow mushrooms. This technology is called "bioconverting technology".
Growing mushrooms can be a valuable method used to fight poverty and starvation. It can make agriculture more efficient and make money for farmers. In 1989 I took part in a project to help people in poverty stricken areas of China learn how to grow mushrooms for self-sufficiency. I was chosen as a mushroom expert because of my success running the Youxi Shanglin Mushroom Farm (cultivating shiitake).
I went to Nanpin county with 20 mushroom science students, to train the local people on how to grow shiitake on sawdust. We took 4 months and helped local people one by one. I also established a mushroom farm as an example.
In Shouling county in Fujian (another place in which I helped), there were 70,000 people in 14,000 families living well below the poverty line with a yearly income of less than 300 Chinese yan (CN$50),
Their land grew lots of scrub wood but little grain. In 1989 we trained them on how to grow mushrooms. 94% of the families were involved. Since then, mushroom cultivation in that county has become more and more economically significant. The average annual income per capita reached 1,800 Chinese yan (CN$300) in 1993, and 75% of it came from mushrooms. The inhabitants are now emerging from extreme poverty to where they can live in more comfortable conditions.
Tree mushrooms can be cultivated in buildings constructed of brick and cement. A heating/cooling system, a ventilation system and shelving are also necessary for indoor cultivation. Alternately they can be cultivated outside in an open field or in the forest, however this type of cultivation is dependent on the climate.
How to grow the mushrooms
To grow tree mushrooms on sawdust is a complicated process, but success will come if procedures are followed carefully. There are 4 stages in the growing cycle:
- spawn running stage,
- substrate preparation stage,
- inoculation stage
- incubation & fruiting stage.
The first stage is the most important and needs the most expensive equipment. An expert or a professional institute usually manages this stage. Growers simply buy the spawn from the experts.
The substrate preparing stage is where the hard work begins. We mix the substrate (sawdust, wheat bran and other supplementary material) and put them in plastic bags. The bags are cooked at 100C for 12 hours, or they are autoclaved at 121C for 2 hrs. The cooking and autoclaving is done to sterilize the substrate and make the media contaminant free. This step is very important.
When the bag is cool, it is ready for the inoculation stage. We use pure spawn to inoculate the substrate. This stage demands a very clean environment and care in handling. During incubation, we check the temperature often and watch the bags for pests and pathogens. When the spawn has run through, they are ready for fruiting.
During fruiting, humidity,temperature and air are all important factors. And for shiitake, lion's mane, and Ling-Zhi, the light intensity is also important.
In summary, tree mushroom production can produce healthy food, create jobs and provide income from agricultural and forest waste. It is a profitable investment for city farmers.
Further readingThe Mushroom Growers' Newsletter