The most comprehensive study of its kind into the quality of organic food and soil has concluded organically grown strawberries are more flavourful and nutritious.

Organic strawberries were found to be tastier by anonymous testers who worked under special lighting conditions so they wouldn't be biased. (iStock)The Washington State University study analyzed 31 chemical and biological soil properties and soil DNA, as well as the taste, quality and nutrition of strawberries grown in 26 commercial fields, half organic and half using conventional farming practices.

Researchers found that strawberries grown on organic farms had significantly higher antioxidant, ascorbic acid and polyphenol levels. They also had a longer shelf life.

Organically managed soils also had greater genetic diversity, making them healthier and more resilient as a growing medium.

"Our findings have global implications and advance what we know about the sustainability benefits of organic farming practices," lead researcher John Reganold said.

'You can have high quality, healthy produce without resorting to an arsenal of pesticides'—John Reganold, Washington State University

"We also show you can have high quality, healthy produce without resorting to an arsenal of pesticides."

Organically grown strawberries also tasted better, according to a panel of anonymous testers.

Working under a red light so the fruit colour would not bias them, the testers consistently judged the organically grown strawberries to be sweeter and have a better flavour than the conventionally grown berries.

The organic food industry has exploded in recent years, growing from $3.6 billion in U.S. sales in 1997 to $21.1 billion in 2008. But while there's been strong evidence that organic food has fewer pesticides, evidence that it's better in terms of taste and nutrition has been scant.

The Washington State University study brought together a multidisciplinary team with expertise in agroecology, soil science, microbial ecology, genetics, food science, sensory science and statistics.

The 26 farm fields that were part of the study were all in California, where 90 per cent of North American strawberries are grown.

"There is no paper in the literature that comprehensively and quantitatively compares so many indices of both food and soil quality at multiple sampling times on so many commercial farms," Reganold said.

The research was published Wednesday in the peer-reviewed online journal PloS ONE.