Straw bale gardens require less soil, less water and hold heat. As the straw breaks down nutrients feed the plants. Combining a straw surround with a hugel interior, topped by lasagne layering is an excellent idea for an area with poor quality soil.
Gardening with straw bales is like container gardening, except the container is compostable and it's nutritious for the plants it cradles. It's also like raised-bed gardening, but without the wood, nails and hammering.