No, you are confusing Green Manure crops with Nitrogen Fixing Bacteria that work in symbiosis with legumes and clover and some other things where the nitrogen i

No, you are confusing Green Manure crops with Nitrogen Fixing Bacteria that work in symbiosis with legumes and clover and some other things where the nitrogen is extracted from the air. With Green Manure you just dig it into the soil or let it die back - many people like to leave the roots to rot in the ground without pulling them up, this is called No Till. It you do pull up a clover you may see small nodules or balls. These contain the bacteria sites - so you can tell this way if your soil has the required bacteria - if not you can buy it in pellet for to add to the soil, or just nab some soil from another garden and put it in yours. Try the plantings again, try more fertiliser, water and remember it takes a few years to get a great garden.