It’s not easily answered. Turn it on its head - when you have a good manure, count the microbes and make that your standard. Then you can add more and see if it improves. The microbes will multiply anyway.
Abhijeet Singh Jim C Philp I have a certain biomanure having its own NPK value. Now if I want to increase its N2 or P concentration, I would like to add some N2 fixing bacteria and P solubilising fungi sp. So I wanted to know in what numerical concentration should I add them to suffice the needs. Is their any mathematical formula or experiment or method to find it? Please correct me if i am wrong at any step as I am new to this research. Thanks
I do not know of such a formula. However, there is a cell density measurement for fertile soils as cfu/g of soil. That also depend on the type of soil and other physicochemical properties. Use the concentration for a fertile soil but like Jim C Philp said, the microbes will multiply and protozoa will feed on them for the purpose of regulation.