I bought some broad beans to plant for the next few months, but had a thought when considering the issue of nitrogen-fixing: that thought being - to what degree does no-dig gardening make nitrogen-fixers unnecessary because one always has the rotting root systems and attendant fungi and bacteria in situ which they produced, which are going to be not only nitrogen rich, but also carbon rich too?
If one cuts off one's produce plants and cuts off weeds to rot, and leaves the roots, and - if appropriate - the leaves and stems to rot back in as a mulch layer, to what extent does nitrogen depletion occur, because most of the biomass is recycled?
A short guide on no-dig -
And a very good basic primer article on soil composition and vitality - the section on "Soil food web" is excellent -
I am still mulling this over. It is another case where a conventional practice is backed by conventional wisdom universalised, but when one rethinks it in a new context, it might not make the same sense. I am not sure that the traditional practice of 'nitrogen fixers' is actually that necessary if one is doing mulch-and-root-cut-no-dig.