There’s quite a lot about ‘lo no or zero’ ’till or tillage’ on the web. Here are some links.
[url=http://en.wikipedia.org/wiki/No-till_farming]Wikipedia[/url]
[url=http://www.no-dig-vegetablegarden.com/no-till-gardening.html]No Dig vegetable Garden[/url]
[url=http://eartheasy.com/blog/2009/01/no-till-gardening/]Earth Easy[/url]
[url=http://www.safecom.org.au/permaculture.htm]Permaculture[/url]
[url=http://www.blitzbrisbane.org/]Permablitz Brisbane[/url]
There are lot’s more