No. Charcoal only mixed in locally with the soil on the plot.
Chalk also over the edges in the same amount like you already did do on the surface of the plot.
I need you to understand the principle: Chalk raises the PH, and keeps on raising it. Charcoal neutralizes/absorbs/buffers/stabilizes the surplus releasing chalk PH down to where it should be in combination with your cow manure.
Hope this helps. But feel free to ask questions in case you are not sure about something.
I want you to succeed as much as you want it yourself. And you'll be getting the full explanation on top as well.
Much is about putting the puzzle together in order to know what you are doing.
Yesterday I was reading on the net and then I found that you get sodium hydroxide when wood ash mixes with water and then I was like “ahaaaaaaa”. I’ve read some chemistry long time before and I’ve even did a laboratory on sodium hydroxide and about its buffer properties. I’ve also done some soap bar at home with olive oil and sodium hydroxide(cold process) so I’m familiar with it. Now I understand why you tell me it buffers the pH. Because that’s exactly what it does.
I just wanted to tell you that. It feels good when you understand what you’re doing and why you’re doing something.