Crop rotation is also important and we rotate the vegetable plots with the chicken or duck pens from time-to-time. Devis (in the photo) does a lot of the work on this. Work in the veg plots is never finished, but well worth it when they bring in a big harvest.
We grow organically and have several large composting areas, like the one you can see in the photo. Kitchen waste such as old veg skins are rotted down, mixed with animal dung and then dug into the ground to prepare for growing veg.