I would like to contribute to this interesting discussion referring the article “Health for acre: meeting the nutrition challenge through organic farming” , written by Dr. Vaibhav Singh and published by the Bija magazine (pag. 6) http://www.navdanya.org/attachments/bija58_27-5-2011.pdf
The article states that since providing nutrition and nourishment are the main aims of agriculture, nutrition per acre is a more accurate measure of productivity than yield of a commodity in a monoculture.
Dr. Singh worked with the data of the 12 studies in India to assess the nutritive value per acre of farmland. These studies show that organic mixed cropping produces more nutrition per acre farmland than conventional monocropping, and that the overall profitability in mixed cropping is higher than in mono-cropping.
According with research organic mixed cropping, on an average, produce more proteins (providing all the essential amino acids) , as well as, vitamins, minerals and micronutrients than those produced by conventional mono cropping.
IFOAM Food Security Campaigner