We also have access to an open source data set published by UC Davis on the physical and nutrient characteristics of charcoal made from more than 1,000 feedstocks. You can interact with the data-set by clicking on the "visualize" button.
For example, we know that charcaol tends to have a high pH, serving as a long-term lime substitute. This chart shows that charcoal tends to increase in pH levels when produced under hotter conditions.
Here is another graph illustrating the pH value of different feedstocks. Please hover over different bubbles to discover their feedstock type and pH value.
So what's the benefit of charcoal if we look at how long it lasts?