I ran across this concept by accident. I'd never heard of it before and even went to the UAF Cooperative Extension Service and no mention is made of it. They do have plenty of information on raised beds.

Anyways, the it's a pretty straight-forward procedure. You set your straw bales on edge in rows and prep them by soaking them with water. The bales will heat up as the decomposition begins. As the temps drop below body temperature levels you take a garden trowel, wedge open a hole big enough to set starter plants in and add a little more potting mix around it. Fertilize and water as you would any garden and your plants should take off. You can also sow seeds directly on the straw bale by covering it with a couple inches or so of potting mix and sowing the seeds as if you were planting them in a jiffy pot or cold frame.

You can grow just about any vegetable plant using this method including potatoes. Ideally, if you have a garden plot that you wish to condition, you can place your bales on them for a couple years and they'll compost down.

Just do a search on Straw Bale Gardening you'll be overwhelmed with information.