[IT IS HARVEST WEEK AT GREENSEEDLING!  This week, we’ll be featuring a timely collection of stories comparing organic and conventional food.   HAPPY THANKSGIVING to our U.S. readership!] Questions about the potential benefits of organic farming center on its differences—or lack thereof—from conventional farming in soil quality, harvest yield, environmental impact, and taste and nutrition.  Greenseedling has already reported on the environmental impact part of this question; now, a side-by-side study of strawberries from commercial organic and conventional farms has reported that organically grown strawberries produce fruit with higher concentrations of some nutrients (but lower of others), had soil of higher quality, and at least one variety that fared better in a blind taste-test.

The study, led by John Reganold of Washington State University, exclusively used commercial farms in California for its data collection; researchers conducted the fruit and soil collection from 2004 to 2005.  Strawberries collected from organic farms yielded smaller fruits with greater dry weight than conventional strawberries; organic strawberries also lost less fresh weight when harvested and tested for shelf-life.  The study did not measure overall yield per acre of the farms.

Additionally, researchers found that organic strawberries had higher concentrations of ascorbic acid (vitamin C) and phenolics and higher antioxidant activity.  Organic strawberries contained less potassium and phosphorus, but the authors of the study note that strawberries are not the best sources of either element and claim that lower phosphorus concentrations may be beneficial in light of increasing phosphorus consumption in the United States.

Researchers also analyzed environmental effects of farming conditions by collecting surface and bottom soils and testing for concentrations of certain elements and nutrients, as well as microbial biomass and genetic diversity.  While the soils had generally similar levels of nutrients, organic soils contained more nitrogen and carbon, which can improve soil fertility and water storage.  Microbes in the organic soils showed greater biomass, genetic diversity, and essential enzymatic activity, such as the ability to convert nitrogen into a form useable by plants and animals.

This strawberry study is unique in its testing of an abundance of quality indicators, as well as its use of a large number of commercial farms.  In nearly all categories, organic farming came out on top, at least in its effects on strawberries.

Discussion question: What are some differences between tests conducted in a lab environment and those done in the field?

News article: http://www.sciencedaily.com/releases/2010/09/100901171553.htm
Journal article: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0012346

Photo: kai-Martin Knaak, GNU Free Documentation License