In reading the discussion document, I am concerned about lack of understanding regarding comparison of organic vs conventional yields. For example, the meta-analysis paper cited from Michigan State faculty (2007) has a number of major flaws. One is that these kinds of studies compare crop yields per se without regard to the time dimension, and in most organic systems there is need for rotation with non-food crops (e.g. legume cover crops), or with food crops that produce lower yields of protein and calories, than in the "conventional" systems being compared.
Another major concern is that a large proportion of the studies cited are from grey literature that is not based on field studies with proper experimental design or use comparisons that typically involve finely tuned organic production systems implemented by people motivated to make organic production successful versus "off-the-shelf" conventional practices that are not fine-tuned for the field in which the experiment is conducted (which is what a reasonable farmer would do).
Hence, findings regarding performance of organic versus conventional systems are biased and unreliable in such meta-analyses because of so many of the studies included in the analysis are of such poor quality (Cassman, 2007).
Citation
Cassman K.G. 2007. Can organic agriculture feed the world—science to the rescue? Renewable Agric. Food Sys. 22:83-83.
In reading the discussion document, I am concerned about lack of understanding regarding comparison of organic vs conventional yields. For example, the meta-analysis paper cited from Michigan State faculty (2007) has a number of major flaws. One is that these kinds of studies compare crop yields per se without regard to the time dimension, and in most organic systems there is need for rotation with non-food crops (e.g. legume cover crops), or with food crops that produce lower yields of protein and calories, than in the "conventional" systems being compared.
Another major concern is that a large proportion of the studies cited are from grey literature that is not based on field studies with proper experimental design or use comparisons that typically involve finely tuned organic production systems implemented by people motivated to make organic production successful versus "off-the-shelf" conventional practices that are not fine-tuned for the field in which the experiment is conducted (which is what a reasonable farmer would do).
Hence, findings regarding performance of organic versus conventional systems are biased and unreliable in such meta-analyses because of so many of the studies included in the analysis are of such poor quality (Cassman, 2007).
Citation
Cassman K.G. 2007. Can organic agriculture feed the world—science to the rescue? Renewable Agric. Food Sys. 22:83-83.