When Jon Frank set out to conduct a unique citizen science project to test the nutrient density of butternut squash, he never imagined the kind of varied results he’d get. Frank, who works with International Ag Labs, a Minnesota-based laboratory that conducts nutrient and soil testing, wanted to see how different growing conditions could affect the crop’s nutrients. He gathered 29 butternut squash samples from growers across the country and had them analyzed by the lab. The samples had been grown in a wide range of settings, from small organic gardens to large conventional farms.
For all samples, the lab measured levels of protein, calcium, phosphorus, potassium, and magnesium. The chart in this article’s slideshow shows the surprisingly wide range of results for each nutrient tested alongside the U.S. Department of Agriculture’s (USDA) stated butternut squash nutrient levels, which represents a composite average based on separate USDA testing. If you look at one of the nutrients — magnesium, for example — you’ll see that the squash with the highest content contained more than three times
The winning squash with the highest average scores across categories was grown and submitted by Doris and Calvin Bey of Harmony Gardens in Fayetteville, Arkansas. Calvin, a retired forest service scientist, and Doris, a retired registered nurse, say they place a strong emphasis on growing nutrient-dense produce. They use biointensive growing methods that go beyond organic, and also teach classes to others on these production techniques. “Meeting minimum organic standards gives no assurance that the produce will be nutrient-dense,” they say. “The added dimension requires having available minerals in the soil in the right amounts and in the correct ratios, plus having an energized soil, with a soil food web that is alive and healthy.”
These data add to a growing body of evidence that how our food is grown is just as important as what we choose to eat. Learn more by comparing the nutrient data for all 29 tested butternut squashes.