What are soil blocks? I first learned about soil blocks after watching The Real Dirt on Farmer John movie. He uses them to start seeds and then I saw that Eliott Coleman recommends them. A block of soil is made and with the right mix will hold together during plant root growth. Once the roots grow into it, it will be more solid. It eliminates the need for flats, peat pots, paper pots and any other pot which can get root bound. In the soil block, roots will air prune and not go beyond outside. It is a messy operation, but for those who like to tinker with things in their workshop, I made a 2" and 3/4" blocker to try out. A soil block is supposed to help minimize transplanting shock. Remember that soil blocks can dry out faster than soil in flats or pots. Keep an eye on them.
This is good for the home hobbyist. If you experience good success and want to try more, I would invest in a professional soil block maker that can do multiples at a time.
See this site for some great advise and ideas on the soil block method. I am not affiliated with it. http://www.pottingblocks.com/
The gentleman who runs the site is very knowledgeable and helpful in returning emails. He also has supplies and square soil block makers at reasonable prices. I learned a lot from all of the content he shares.