The wood chips can be any species including black walnut and pine. You must have leaf brances mixed in. This is where the nutrients come from.

Little to no water is needed. Watch "L2survive" youtube channel.

He feeds his chickens garden and yard waste and adds chips. Every year or three he screens a layer into the garden in the fall. Layer everthing. All ash from heating goes into chicken yard, egg shells, kitchen waste, ect.

Lay flooring construction paper over grass and use 6 inches of leaf/chip. First year or two needs blood meal fertilizer. Pull back chips and plant in soil, plant gets half a foot, push back chips. Every fall add 6 inches until it builds up. Then as topping if wanted. Continue layering chicken yard soil in garden. The PhD's came and measured the soil. It's 10x - 50× above baseline in nutrients.