Soil amendments for healthier spinach

Thursday, April 12th, 2018

Kaine Korzekwa

Soil health is of great importance in crop production, but what about nutrition? Soil health can often impact the vitamins, nutrients and even toxins found in the produce that is consumed. Soil scientists often work to mitigate these toxins to keep them from entering the food supply.

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 soil

A field within the experimental site is ploughed by a local farmer. Photo credit Richard Smith.

In 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.”

Read more about soil amendments and soil health here.