Science News

To keep soil health, scientists say mix up plant species

Soil health is deteriorating around the globe. A combination of commercial agricultural practices, global warming and pollution are draining nutrients and encouraging the accumulation of contaminants.

The solution, scientists say, is biodiversity. New research highlights the importance of soil structure for soil health.

As a new paper in the journal Ecology Letters explains, the best way to maintain proper soil structure is to increase the diversity of plant species.

Soil relies on plant roots for water and protection from erosion. While the roots of some species are especially good at keeping soil well-watered, the roots of other species are superior at preventing erosion.

When experimenting with different ratios of grasses, herbs and legumes in vulnerable grasslands, researchers found maximizing diversity yielded the healthiest soil. At field sites in both England and Germany, plant biodiversity proved the most effective way to maintain soil health.

What can happen when soil becomes overworked and depleted of nutrients? Researchers say look at the Dust Bowl. In the 1930s, drought and poor farming methods throughout the prairies of the United States and Canada yielded unproductive soil, resulting in food shortages and mass migration.

“Improving the physical structure of soil is vital for conserving water, reducing flooding and water pollution,” John Quinton, a professor of environmental sciences at Lancaster University, said in a news release. “Our findings demonstrate that increasing plant biodiversity improves the physical properties of soil and have the potential to help us develop new, greener solutions for these issues.”

“Soils are severely degraded in many parts of the world and these findings suggest that enhancing plant diversity could be an important way of speeding up their restoration to bring back fertility,” added Richard Bardgett of the University of Manchester. “It is almost like different combinations of roots can be used to engineer the soil, working to enhance its physical structure which is key to soil health.”