How does Charcoal effect the the soil?


A customer has a question or concerns and I hope we can get some opinions on it, thanks.

How does Charcoal effect the the soil?


Wood ashes were often used by farmers to change the ph of soil raising ph
There appears to be some confusion about the effect of charcoal on the pH of the soil. Charcoal is generally alkaline to varying degrees, but a found some sources claiming that it can be used to LOWER the pH of the water used in Hydroponics!

The pH issue might not be a concern either way though, since very little charcoal in the soil still has a beneficial effect. One scholarly article I read claimed that just 1% charcoal by weight in the soil is enough to reap the benefits.

So here’s my question: would adding charcoal to a soil at the rate of 1% really make it any more alkaline, even if the charcoal had a pH of 8 or 9?