Hugelkultur is a fantastic method of providing your crops a continuous supply of moisture and nutrients - with the help of rotting wood at the core.
Before you plant, you create a large center of wood: twigs, branches, logs or even whole trees. Over time the beds are loaded with organic material, nutrients and air pockets for the roots of what you plant. Eventually the deep soil of the hugelkultur bed becomes incredibly rich and loaded with soil life.
As the wood shrinks, it makes more tiny air pockets - so your hugelkultur becomes sort of self tilling. The first few years, the composting process will slightly warm your soil giving you a slightly longer growing season.
It works equally well in urban lots or large acreage.
On a small scale, it can reduce irrigation needs. On a large scale it can eliminate irrigation needs. Hugelkultur has even proven to be a successful method of growing crops in the desert with no irrigation!