Likewise, the American Journal of Clinical Nutrition published a similar study in 2010 looking at over 50 years of research and reached a similar conclusion. (Dangour et al, Am J Clin Nutr. 2010: 92:203-10.)
My purely anecdotal conclusion from my own farming operation would concur with the results of these reviews. The nutritional value of what you eat is a direct result of the quality of the soil it is grown in. The soil quality is not dependent on a "farming system" ie: organic or conventional. Soil quality is contingent on the care and stewardship of the farmer farming the land. Care and stewardship are not "farming systems" but philosophies that work within both farming systems. Care and stewardship are not mutually exclusive to conventional farming. Visit a family farm and you will discover quite the opposite is true.
Soil condition and quality is a direct result of care and stewardship and will reflect the nutrients of that care and stewardship, as well as the nutrients that are inherent to that particular soil type. If a soil is low in boron, the food grown there is likely to be low in boron. If a soil is high in iron, the food is likely to be higher in iron than food grown in iron deficient soils. There is a direct correlation between the nutrients in the soil and the nutrients in your food grown from that soil regardless of whether that farmland is organic or conventional.
Some folks will say "well organic farmers take better care of their soils with organic practices." Let's take a closer look at that premise...
Wikepedia defines organic farming as "uses a variety of methods to improve soil fertility, including crop rotation, cover cropping, reduced tillage, and application of compost. By reducing tillage, soil is not inverted and exposed to air; less carbon is lost to the atmosphere resulting in more soil organic carbon. This has an added benefit of carbon sequestration which can reduce green house gases and aid in reversing climate change."
Jeez, sounds like my farm... which is conventional...
OK, let's look at those practices:
Crop rotation - yup we do that. We do that so that we build up the soils and reduce the likelihood of pest resistance by repeatedly planting the same thing in the same field year after year.
See this field of edible/tofu soybeans? Last year it was planted in corn.
Next year it will be back in corn or hay or tomatoes or green beans. We rotate our crops annually. Always have. Always will. Period. Conventionally.
Green manures & cover crops - yup, we do have and have for 40+ years.
No-till/conservation till - yup, we do that.
Integrated Pest Management - yup we do that.
So back to the food fight. We as conventional farmers practice very similarly to organic farmers. It is our goal to be constantly improving our soils through the many practices that are often credited to "organic" farming systems. We adhere to the pre-harvest intervals so that our buyers can trust the foods that we grow do not have unsafe levels of residues. As I've said in numerous blogs, my kids eat what we grow, and they are of utmost importance to me. If I wasn't comfortable feeding them what we grow, then we wouldn't farm the way we do.
There is not a food fight between us as farmers. We have good friends and neighbors who are certified organic. We all get along which is why it amazes me that this choice between organic and conventional is so polarized amongst consumers. As a farmer, I want you to support farmers of all kinds. If you choose organic foods, your supporting a farmer. If you choose conventional foods, your supporting a farmer. As a dietitian, I want you to eat healthy foods and know that you can do so from both organic and conventional. Despite the media frenzy around the study, I don't think this really is a food fight. It is your choice as a consumer and we are fortunate to have as many safe and healthy food choices as we do thanks to all the American farmers, organic and conventional.