News Releases


Facebook   Twitter
Soil Science Society of America
5585 Guilford Road • Madison, WI 53711-5801 • 608-273-8080 • Fax 608-273-2021
www.soils.org
Twitter | Facebook | RSS News Release Feed

NEWS RELEASE
Contact: Susan V. Fisk, Public Relations Director, 608-273-8091, sfisk@sciencesocieties.org

Soil amendments for healthier spinach

Combo of biosolids, zinc, limestone prevents toxic uptake

Oct. 4, 2017 - Soils keep plants healthy by providing plants with water, helpful minerals, and microbes, among other benefits. But what if the soil also contains toxic elements?

Field with cadmium-heavy soilIn areas like Salinas Valley, California, the soils are naturally rich in the element cadmium. Leafy vegetables grown in these soils can take up the cadmium and become harmful to humans. What to do? The solution goes back to the soil. Adrian Paul, a former researcher now working in the Sustainable Mineral Institute in Brisbane, Australia, is working to find which soil additives work best.

Cadmium appears in very low levels or in forms that prevent contamination in soils across the world. However, some soils, like those in this California study, naturally have more than others. It can result from the erosion of local rock formations. In some instances, it’s present due to human activity. Metal processing, fertilizer or fossil fuel combustion, for example, can leave cadmium behind.

Cadmium may decrease people’s kidney function and bone density. As a result, international guidelines set safety limits on cadmium found in food. Growers with otherwise fertile fields need to grow food within these safe levels. Their livelihood depends on it.

“Our research aims to protect local producers and consumers by lowering the cadmium in vegetables. This gives producers the ability to grow safe, profitable crops,” Paul says. “Consumers need to be able to safely eat what the farmers grow.”

Paul worked with four additives: zinc and manganese salts, limestone, and biosolids compost. (Biosolids are nutrient-rich organic materials from sewage processed at a treatment facility. They are typically used to improve soil’s physical and chemical characteristics and fertilize the soil.)

Spinach plants grown in greenhouse in cadmium-heavy soilAlthough each works in a slightly different manner, the soil amendments generally solve the cadmium problem in two ways. They can prevent the passage of cadmium from the soil to the plant by offering competing nutrients. They can also chemically alter the cadmium so it is unavailable.

The researchers found that a combination of compost, zinc, and limestone brought the levels of cadmium in spinach down to nontoxic levels. The next step in this work is to better determine the ideal combination of the soil amendments. Researchers also want to study vegetables besides spinach, and other elements. 

“Farmlands provide for us all,” Paul says. ”Rehabilitating agricultural fields, by removing heavy metals like cadmium, means healthier soils and healthier food.”

For this research, Paul worked with Rufus Chaney and his team. Read more about this study in the Journal of Environmental Quality. This research was done in collaboration with researchers at the USDA Agricultural Research Service.

The Journal of Environmental Quality is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.

The Soil Science Society of America (SSSA) is a progressive, international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, SSSA is the professional home for 6,000+ members dedicated to advancing the field of soil science. It provides information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management, recycling, and wise land use.

SSSA supports its members by providing quality research-based publications, educational programs, certifications, and science policy initiatives via a Washington, DC, office. Founded in 1936, SSSA proudly celebrated its 75th Anniversary in 2011. For more information, visit www.soils.org or follow @SSSA_soils on Twitter.