Iowa Learning Farms has been spreading the word about soil health, and its preservation, for over a decade, and Iowa farmers have long touted the benefits of soil health for crop growth. Now, the importance of soil is gaining an even wider audience when earlier this year researchers from the University of Colorado-Boulder published findings of a study leading to the first global atlas of soil bacterial communities.
Researchers at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado-Boulder published their study in the January issue of the highly respected journal, Science. Analyzing 237 soil samples from eighteen countries across six continents of varying climates, the researchers discovered that 2% of soil bacteria—about 500 species—accounted for nearly half of the soil bacterial communities found worldwide!
Images of soil bacteria from the dominant Proteobacteria and Actinobacteria phylotypes courtesy of MicrobeWiki.
While scientists have long known that soil bacteria make up a substantial percentage of earth’s living biomass, contributing to plant productivity, carbon cycling, and nutrient availability, the immense numbers and diversity of soil bacteria (total counts are estimated to be in the tens of thousands!) have kept them from fully understanding soil bacterial distribution and function. The CIRES study is a major breakthrough in soil science as it documents the most abundant and dominant types of soil bacteria found worldwide.
CIRES researchers believe this discovery sets up a “most wanted list” of soil bacteria, as it points to which bacteria should be targeted in future studies seeking to understand soil microbes and their contribution to soil fertility and ecosystem functioning. The next step is to begin categorizing these dominant bacteria into groups of co-occurring bacteria and habitat preferences, resulting in data that the CIRES group hopes will shed more light on the function of certain groups of bacteria, eventually leading to agricultural applications.
The full journal article from Science can be viewed at A global atlas of the dominant bacteria found in soil.