What lies beneath your feet shows more activity and tells more stories than you might realize.
MANHATTAN, Kan. – In a lab at Kansas State University, soil microbiologist Chuck Rice pours red-colored water from a flask through a funnel filled with soil. After several seconds, the water drips from the funnel into a beaker, but this time the water runs clear. The demonstration shows how soil can improve water quality, but that’s only one of the many benefits of this often-overlooked, finite natural resource.
“Soil is extremely important to the planet, but people might not think it’s important,” said Rice who is a distinguished professor of agronomy. “They walk on it, but they don’t see inside the soil. Water you can see as it flows. You can see if it’s contaminated or dirty. With air, you’re breathing it. You can see smoke in the air, or pollution. But, soils aren’t something we think about every day.”
To increase awareness about its importance, Dec. 5 has been designated World Soil Day. It was first celebrated in 2002, when the International Union of Soil Sciences made a resolution to make the celebratory annual event on that date. In 2013, the Food and Agriculture Organization (FAO) of the United Nations also adopted Dec. 5 as World Soil Day.
This year’s designation will kick off an even bigger event to recognize soil and its many uses. The International Year of Soils will take place in 2015, with each month emphasizing a different benefit of soil.
Food production and beyond
When people think about soil, particularly in rural Kansas, Rice said, they probably first think about its use to grow food.
“Soils have a much broader function than just producing food,” he said. “Soils not only help provide clean water, but they help regulate floods. When it rains, the water soaks into the soil if there is good soil quality, rather than running off and flooding downstream.”
“(Soils) also regulate climate, because carbon is stored in soils,” he continued. “If you look at different religions, soil is an important part of faith in some cultures. Then there’s art. Soils come in many different colors, and people can use those colors to do paintings or use other features of soils as part of art.”
Soil supports rural life as well as urban life, Rice said, as many landscapers and horticulturalists rely on it for trees, plants, flowers and gardens. Soil also helps support buildings and infrastructure in cities and communities.
Perhaps one of the most important uses for soil is that it can directly improve human health. In a spoonful of soil, Rice said about 10 billion different microorganisms exist. Yet, scientists only know 1 percent of those organisms. Finding out the other 99 percent could lead to some of the greatest scientific breakthroughs.
“Eighty percent of our antibiotics today actually came from soil,” he said. “The first antibiotic, penicillin, was discovered from dust blowing into petri plates by (Alexander) Fleming.”
In the 1940s, Selman Waksman was credited for discovering streptomycin, among several other antibiotics, Rice said. Streptomycin was discovered from soil and served as the first effective treatment for tuberculosis. For his work, Waksman was the first soil microbiologist to win a Nobel Prize.
In addition to antibiotics, soils have helped create many cancer treatment drugs. In a review of these drugs, Rice found 60 percent come from natural products, including soils.
Appreciation of variety
Not all soils are the same, Rice said, as they often differ in color, texture and even origin.
“Clay, silt and sand are the basic units of soil,” he said. “Some areas might have real sandy soil. Water will drain fast, but it doesn’t have a lot of nutrients. They generally are less productive. If you have mostly clay soil, when it rains, water doesn’t move through the soil very fast, so a lot of it runs off. A better soil from a farming standpoint is in the silt loams or silty-clay loams. Silty soil has good infiltration rates for water to move in, a lot of organic matter and good structure for root growth.”
Soils that originate in different parts of the world, and even different parts of the United States, vary because they are comprised of different materials.
“In Manhattan, Kansas, a lot of soils developed from wind-blown material that came in from the West Coast and tend to be silty in nature,” Rice said. “Also some of our soils come from our limestone in the Flint Hills. As you go to Alaska or the coasts of Washington or Oregon, for example, much of those soils form from volcanic ash and rock. They have completely different characteristics than soils in Kansas.”
To find out more about soils specific to the United States, the U.S. Department of Agriculture’s Natural Resources Conservation Service has soil survey data and classification information on its website.
To watch a video about World Soil Day and the importance of soils to help sustain life, go to the K-State Research and Extension YouTube page.
The World Soil Day theme for 2014 is “Soils, foundation for family farming.” You can learn more about World Soil Day on the FAO website.
The Soil Science Society of America, with the Global Soil Partnership, has numerous resources for the public, teachers and children about soil and each monthly theme for the International Year of Soils.