In celebration of the International Year of Soil 2015 (IYS), the Soil Science Society of America (SSSA) is coordinating a series of activities throughout to educate the public about the importance of soil. April’s theme is “Soils Clean and Capture Water.”
According to IYS monthly leader Gary Pierzynski, “soil is a great water purifier. There are three ways that soil cleans water: physical, chemical and biological.” Here are some facts from Pierzynski, a soil science professor at Kansas State University.
Physical: the particles of soil act like a filter. The ideal soil has a distribution of pore sizes so it can filter water, while also allowing the water to pass through the soil.
Chemical: soil particles have a negative charge! That means that positive ions like calcium, magnesium and potassium can all be removed from passing water and retained by the soil. This is good, because each of these ions is a nutrient for plants! Some contaminants can be removed by this mechanism as well.
Biological: soil is the largest bioreactor on the planet. Within the soil, bacteria and fungi transform and decompose certain chemicals. Soil microbes can change organic forms of nitrogen into ammonium ions—and even into nitrogen gas. They can also decompose some organic pollutants!
As part of their celebration of IYS, SSSA is developing a series of twelve 2-minute educational videos. April’s Soils Clean and Capture Water video can be viewed at www.soils.org/iys/monthly-videos. Educational materials can be viewed at www.soils.org/iys by clicking on the April tab.