Last fall I laid down wood chips on several beds. Where I planted garlic, it's coming up strong and looking better than in past seasons. There is good research conducted at Laval University in Canada on this subject. There are folks here on Permies who have been using chips for several years with good results and have not had the problems with nitrogen depletion. The information I have read, and more interesting, is my visit to Paul's place who was in the video. He has never had any nitrogen problem. Google his name and look at the videos, he explains so much about what he is doing. Makes sense, follow nature.
Here is a link that may be of help.
http://www.dirtdoctor.com/view_org_research.php?id=69
