Hi John,
I see now where your coming from. I should have read your initial post more closely.
You are trying to build your heap from materials sourced only from your plot?
I’m reasonably certain that you won’t be able to do this at least not on any viable scale.
I can’t see how you would source the required ratio of greens and browns solely from the materials available from your plot.
You will of course accumulate material from the crops you grow but you are also going to need to add other materials such as Cardboard, Newspaper, Autumn Leaves, Grass clippings to name but a few.
“Best Practice” usually carries the proviso “where possible”.