Help with detect/replace block

So i've been creating a solarpunk, in wich the main focus is to terraform the earth. I´m in the middle of creating a soil purifier, i already have the block and textures sorted out but i need help on the procedures part. My plan was to make the block that when provided with seeds, would, at a random tick speed, detect if there is any corrrupted soil and purify it.

Does anyone know of a way to do so?

Thanks a lot :)