Grow buckwheat or clover first, then add some compost and a mix of blood and bone meal along with wood ashes or gypsum. My garden is 5 beds. I shift the plants over to the next bed each year so as to not plant the same thing in a specific bed each year. For the container gardener this would mean the same thing - you planted potatoes in this container this year, plant lettuce or beans next year in this container!
Offered by Roger.
Yes, growing clover after or before you put in your plants, is a very good idea, because inside the clover-roots, lives a bacteria, that can take the nitrogen out of the air and put it into the ground.
Offered by Jeroen.