I built a fenced enclosure and cultivated sweet potatoes and yams in it. I originally had a small 3X3 m garden behind the wattle and daub hut that already had some sweet potato and yam vines growing in it that were planted after the hut was built. But wallabies kept eating the leaves. So I made a wattle enclosure around it to keep them out. Wood ash was added to the soil to provide potassium and phosphorus for the growing tubers.
The sweet potato is a remarkable plant. It’s a staple food of many traditional cultures. NASA has considered it a potential crop to be grown on spaceships for long term missions. In terms of energy production it’s only 3rd behind sugar cane and cassava. It produces the most food value (a combination of edible energy and nutrition) of any crop per unit space and time.