Washington State University researchers say they’ve found that organically grown strawberries are more nutritious, flavorful and have a longer shelf life than conventionally grown strawberries. They also leave soil healthier.
John Reganold, WSU professor of soil science, authored the strawberry study, which was published by the Public Library of Science in its online journal, PLoS ONE. According to Reganold, “Our findings have global implications and advance what we know about the sustainability benefits of organic farming systems.”
The study received federal funding and was supported by The Organic Center, which promotes organic food and is sponsored by major organic companies. Reganold’s team included Preston Andrews, an associate professor of horticulture, and seven other experts, mostly from WSU.
They compared the taste and nutrition of strawberries grown in 13 conventional and 13 organic commercial fields over two years in California, and also analyzed 31 chemical and biological properties and soil properties, in what they say was the most comprehensive study of its kind.
On almost every major indicator, Reganold and his team found the organic fields produced berries equal to or better than the conventional fields. They found that the organic soils had more nutrients and the strawberries themselves had higher concentrations of antioxidants and vitamin C.
Among the study’s findings, as reported in a press release by Washington State University:
• The organic soil was chemically and biologically superior, with key properties including carbon sequestration, nitrogen, enzyme activities and micronutrients.
• The organic strawberries remained mold-free and more appetizing about a half-day longer than the conventionally grown berries.
• The organic strawberries had more dry matter, or, “more strawberry in the strawberry.”
The study used testers, working at times under red light so the fruit color would not bias them, who found that one variety of organic strawberries was sweeter, had better flavor and, once a white light was turned on, better appearance. The testers judged the other two varieties to be similar.
California, which produces 90 percent of the nation’s strawberries, is at the center of a debate over the use of soil fumigants to prepare fields for planting.
Conventional farms in the WSU study used methyl-bromide, an ozone-depleting chemical, which is slated to be replaced by the highly toxic methyl iodide, despite protests from health advocates and members of the National Academy of Sciences.
The WSU study’s DNA analysis of the chemical-free organic soils found that they “had dramatically more total and unique genes and greater genetic diversity,” which the researchers explain are key measures of the soil’s resilience to stress and ability to grow crops.
Reganold said the study’s evidence that organic strawberries are superior berries shows that “you can have high quality, healthy produce without resorting to an arsenal of pesticides.”