All around the globe, fertile soils are disappearing at an alarming rate. At the beginning of the 20th century, the topsoil in Iowa was an average of 14-18 inches in depth. By the end of the 20th century, topsoil depth had reached an average of only 6-8 inches. If that trend continues, Iowa will lose virtually all of its nutrient rich topsoil within the next 100 years. Considering that Iowa is the United States' top exporter of soybeans, corn, and grain, the loss of fertile soil here has huge implications. Iowa is unfortunately just one of many places where fertile soils are disappearing. Industrial activity, deforestation, intensive agricultural practices, and climate change are all contributing factors. An estimated 12 million hectares of land are lost annually to desertification alone.
In recent years, scientists have been working on methods for improving and maintaining soil health. One proposed method is the use of perennial crops. An advantage of perennial crops is that they can regrow without having to be re-sown, reducing the number of times a soil must be tilled. Tilling is damaging to the soil, so doing it as little as possible helps keep the soil healthy. Since perennials don't die at the end of the season, they maintain complex root systems beneath the soil year round. Those roots hold the soil together, helping to prevent erosion. While there aren't currently a lot of good perennial crops available, groups like The Land Institute are working hard to develop a new generation of perennials to replace our current crops. Another idea for improving soil health involves the targeted used of microbes in soils. Soil scientists are currently attempting to identify bacteria that could help reverse the effects of degradation. By adding specific microbes to the soil, researchers hope to strengthen the soil's natural rhizosphere, thereby making a healthier soil. Regardless of what techniques we use to address the problem, if we want access to fertile soils in the future, we must take actions in the present.