How the C/N ratio affects the Yield


Mushrooms can decompose various lignocellulosic substrates. As these substrates have different carbon-nitrogen ratios, today’s research paper studies the effect of the carbon-nitrogen ratio on the yield and size of Pleurotus pulmonarius. For the primary substrate, the authors used corncobs, wastepaper, and sawdust.

These substrates had the following carbon-nitrogen ratios—120 for wastepaper, 400 for sawdust, and 325 for corncob.

When it comes to the stipe length, the authors found that using corncobs lead to the longest stipe, followed by sawdust and then wastepaper. In addition, they found that the stipe length for the second flush is shorter than for the first flush.

The same pattern can be found for the pileus diameter. Using corncob as the primary substrate led to the largest pileus, followed by sawdust and then wastepaper. Again, the second flush produces smaller pileus than the first flush.

If we look at the total weight, we see that corncob reached 139g, the highest value, followed by 129g for wastepaper and 114g for sawdust. These values are split the following way between the first and second flush. For the corncob, 86g to 53g, 79g to 50g for wastepaper, and 72g to 42g for sawdust. Or roughly a split of 62% for the first flush to 38% for the second flush.

The biological efficiencies were 70% for corncob, 64% for wastepaper, and 57% for sawdust.

As the question was if the carbon-nitrogen ratio affects this parameter, we will take a look at the correlations between them. If we plot the carbon-nitrogen ratio against the total weight, we get the following graph that looks at first glance that there is no effect. To see the effect clearer, we add a trend line into the graph. This line indicates a slight decline in total weight with higher carbon-nitrogen ratios.

For the stipe length, the effect is positive. Meaning, the higher the carbon-nitrogen ratio, the longer the stipe length.

The same is true for the pileus diameter. The higher the carbon-nitrogen ratio, the larger the pileus.

Overall, we can conclude that the carbon-nitrogen ratio affects the yield and size of the mushroom.

But as the authors used only three different types of substrate types, further studies have to be made to come to a final conclusion. If you want to learn more about the carbon-nitrogen ratio, then the video on the right is for you.

In this video, I show how Pleurotus ostreatus and Pleurotus Florida react to different carbon-nitrogen ratios and the optimum carbon-nitrogen ratios for other mushrooms.

Talk to you there.


📝Osunde, M.O., Olayinka, A., Fashina, C.D. and Torimiro, N. (2019) Effect of Carbon-Nitrogen Ratios of Lignocellulosic Substrates on the Yield of Mushroom (Pleurotus pulmonarius ). Open Access Library Journal , 6: e5777.,