SEATTLE, WASHINGTON, US — Farms that used regenerative agriculture practices such as no-till farming, cover crops and diverse crop rotations produced crops with higher levels of certain vitamins, minerals and phytochemicals than farms using conventional practices, according to results in a study from the University of Washington.
The study appeared Jan. 27 in PeerJ. When compared to crops from conventional farms, crops from regenerative agriculture farms had 34% more vitamin K, 15% more vitamin E, 14% more vitamin B1 and 17% more vitamin B2. The regenerative agriculture crops also had 11% more calcium, 16% more phosphorus and 27% more copper.
“We couldn’t find studies that related directly to how the health of the soil affects what gets into crops,” said David R. Montgomery, PhD, lead author and a professor of Earth and spaces sciences at the University of Washington. “So we did the experiment that we wished was out there.”
The Dillon Family Foundation provided a grant to the study’s authors. Two of the authors, Dr. Montgomery and his wife Anna Biklé, work for Dig2Grow.com, which covers environmental issues. Two other authors, Paul Brown and Jazmin Jordan, raise cattle and sheep at Brown’s Ranch in Bismarck, North Dakota, US, a farm that uses regenerative agriculture and was sampled in the study.
The study included crops from farms following soil-friendly regenerative practices for at least five years. The researchers tested the influence of soil health and soil health scores on the nutrient density of crops by measuring eight pairs of farms using regenerative agriculture practices or conventional practices in the states of North Carolina, Pennsylvania, Ohio, Iowa, Tennessee, Kansas, North Dakota and Montana. Each regenerative agriculture farm was paired with a nearby conventional farm that grew the same crop variety, such as peas, sorghum, corn or soybeans.
“The goal was to try to get some direct comparisons where you controlled for key variables: The crop is the same, the climate is the same, the weather is the same because they’re right next to each other, the soil is the same in terms of soil type, but it’s been farmed quite differently for at least five years,” Montgomery said.
The study also compared wheat crops. Regenerative wheat crops were planted in a crop rotation pattern that included cover crops between crops of spring barley and winter wheat. The regenerative wheat samples had 41% more boron, 29% more magnesium, 48% more calcium and 56% more zinc than conventional wheat samples.
Among crops grown for animal feed, comparisons were made for the unsaturated fatty acid profile of beef and pork. The regenerative crops had higher levels of omega-3 fatty acids and a healthier ratio of omega-6 fatty acids to omega-3 fatty acids. Beef from cattle that ate feed from regenerative crops had more than half the amount of omega-3 fatty acids when compared to beef from cattle that ate feed from conventional crops. Pork from pigs that ate feed from regenerative crops had more omega-3 fatty acids, including 11 times as much alpha-linolenic acid (ALA) and two times as much eicosapentaenoic acid (EPA) when compared to beef from pigs that ate feed from conventional crops.
“The biggest criticism I would have of this study is small sample size,” Montgomery said. “That’s why the paper’s title includes the word preliminary. I’d like to see a lot more studies start quantifying how do differences in soil health affect the quality of crops that come from that land?”