Here is a link to the Organic Cropping Systems Project that Cornell has been working on involving some of Anne and Eric Nordell’s methods. The summary on this page is brief but there are many pdfs on the left side that can be downloaded. It is some interesting reading, but does not involve the use of animals at all, but rather studies different systems of tillage, cover cropping, rotation or lack of such to produce high value vegetable crops. I just found these and have not read through them yet, but rumor has it that the weed control that was hoped for with the Nordell similar system was not obtained due to the large weed seed bank at the Freeville farm where the study was done.
http://www.hort.cornell.edu/extension/organic/ocs/vege/index.html
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