Scientists Found That You Can Grow Better Blueberries by Ditching the Fertilizer

Blueberries, bite-sized and brilliantly colored, have been lauded for their health-enhancing antioxidant properties. Antioxidants are compounds that prevent or delay cell damage, and while they naturally occur in the popular berries, how the bushes are grown can impact their production levels. In a new study, researchers have found that the best way to maximize the healthiness of blueberries is to add a little grass.

Intercropping, the system of growing different crops in close proximity, allows for different plants to benefit from each other, and presents a sustainable alternative to chemical fertilizers. Researchers from the University of Chile have now determined a simple, ideal growing partner for blueberries, and reported their findings in the journal Frontiers.

Blueberries grow best in wet, acidic soils. In drier and more alkaline soils, the bushes are unable to pull essential iron from the soil. José Covarrubias, senior author of the study and an agricultural scientist at the University of Chile, said in a statement that blueberries “lack these adaptations because they evolved in uncommonly wet, acid conditions, which dissolve the iron for them.”

“Iron is essential for the formation and function of plant molecules like chlorophyll that allow them to use energy,” Covarrubias said, and in blueberry bushes, that deficiency starves the enzymes they need to produce those coveted “superfruit” antioxidants.

Industrial farms without the right soil usually correct this by artificially acidifying the soil or applying synthetic, iron-rich fertilizer. Both approaches are expensive, and not any good for the environment. Grasses, however, naturally grow just fine in poor soils—and their roots provide an organic source of iron for fruiting plants growing among them. “Intercropping with grass species has been shown to improve plant growth and fruit yield in olives, grapes, citrus varieties—and most recently, in blueberries,” Covarrubias said.

Though this study offers a safe, cheap alternative to fertilizers, there are drawbacks. Intercropping requires more water than the old way, and the researchers found that the grasses caused blueberries to lose some of their firmness. And that is a bummer, because there’s nothing like that classic blueberry POP! when you bite into a juicy one.

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