Classical Substrate vs. Synthetic Substrate | White Button Mushroom


Agaricus bisporus, known as the button mushroom, is one of the most widely produced mushrooms worldwide. As this mushroom is a secondary decomposer, it grows only on already decomposed substrates which traditionally consists of straw, manure, gypsum, and urea.

To make viable mushroom cultivation using alternative raw materials, one must consider the availability, transport, seasonality, and costs of these materials. Besides, the ideal carbon-to-nitrogen ratio has to be evaluated.

The authors of today’s research paper, therefore, tested two different types of compost. They called the compost containing manure ‘classical’ and the compost containing no manure ‘synthetic.’ The primary substrate for both composts was sugarcane bagasse and sugarcane straw.

To prepare the substrates, the authors followed the following protocol.

7 days before the composting, they wetted sugarcane straw.

3 days later, they added the bagasse and wetted the whole mixture.

After 3 more days, nitrogen supplements, calcium carbonate, and calcium sulfate were added, and the pile was thoroughly mixed.

At this moment, the composting process starts.

3 days later, the moisture content was measured and, if needed, adjusted. On the same day, the pile got mixed.

This step is repeated on days 5, 7, and 10.

On day 10, the authors added more calcium sulfate to the mix.

The next day, the compost was filled into the pasteurization chamber and pasteurized for 8 hours at 59°C. After this period, the compost was conditioned for 10 days at 48°C.

On day 4, after adding the nitrogen sources and supplements, the temperature of the piles started to increase to around 70°C. This temperature could be maintained over five days. The authors noted that the classical compost had around 11% higher temperature than the synthetic compost.

On the other hand, during the whole process, the moisture content of the compost starts to decline from around 80% to 67%. While at the same time, the pH value increase from 6,3 to 6,8. These changes lead to a decrease in organic matter and the C: N ratio.

At the end of 25 days of production, the authors found no statistical difference in the five different strains used. They found an average yield of 23.8% for classical compost and 15.7% for synthetic compost.

While the authors could show that alternative substrates can produce button mushrooms, the difference of 8 percentage points between the classical and the synthetic compost is too significant to be ignored. It directly impacts the production costs and, therefore, the revenue generated.

On the other side, the impact of the nitrogen outflow of the classical compost into the environment and the pungent odor cannot be ignored.

With that in mind, the new substrate formulas should not be ignored. Especially because there might be a new market of non-consumption that is more likely to pay a higher price if the environmental impact can be addressed.

If you are interested to learn more about this new customer base, then the video on the right is for you.

Talk to you there.


📝 João P. F. Jesus, Carolina B. Kohori, Meire C. N. AndradeJoão P. F. Jesus, Carolina B. Kohori, Meire C. N. Yield of different white button strains in sugar cane by product-based composts. Academic Journals, Vol.8(9), pp. 824-831, March 2013.