5 Hours Ago
I worked for an organic farmer in Schweiz back in the 70es.
From what he told me, Steve is quite right about the nitrogen.
As the cover crop breaks down, the nitrogen level goes down, but later goes up again.
So you need to time it right in order to have that nitrogen on hand for your follow up crop.
I don't know what your soil is like, but on our dense, fairly compact soil, a cover vrop with deep roots does wonders to loosen the soil structure.
I use Phacelia in my garden.