Hi compostpope
I have been developing a self sustaining composting system for nearly 20 years and I`m learning all the time. I have several allotments varying from loamy clay to sandy loam. My oldest plot (20 yrs) has been improving in productivity year on year and is now very fertile. I mainly grow comfrey (permanent bed about 10% of total plot), alfalfa, grazing rye and phacelia. Alfalfa is longer term and is occupying about 10% from August for about 18 months. I suppose I have about 25% occupied by green manures in the growing season but I try to minimise bare ground in winter by sowing shorter term stuff such as phacelia and field beans. Rye forms the most bulk and is followed by leeks around May/June leaving a little for seed saving. Alfalfa needs to be sown before the end of August here and usually follows my onion crop. Rye can be sown quite late but September is best and usually follows my potato crop. NOTE: I do not dig anything in. Everything goes in the compost bin and I try to get it suitable for mulching as soon as possible. This usually depends how quickly the rye has decomposed. I probably cut the comfrey and alafalfa twice during the growing season depending on the season. Most of the resulting compost is put on my brassica bed in autumn or spring but some is used to mulch fruit and squashes.
Hope this helps
Pete