Soil: just dirt?
Soil is where the circle of life begins and ends and begins again, as plants take up soil nutrients, herbivores eat plants and carnivores eat herbivores and wastes return to replenish the soil again. Within the soil, microbes are the missing link between death and life, breaking down organic material and releasing raw mineral nutrients. Soil isn’t just dirt: it is home to up to 10 billion microorganisms—per gram!
Around the world, the people most dependent on healthy soil microbial dynamics may not even be aware of these unseen biological processes. Today, high soil degradation and low access to fertilizers critically intersect with unmet nutritional needs in sub-Saharan Africa. Soils become degraded when crop residues are removed, perhaps to feed livestock, without adequate fertilizer use. The soil’s naturally rich nutrient reserve, organic matter, becomes exhausted. Tillage speeds up organic matter depletion by mixing the soil and stimulating microbial degradation. This disturbance also destroys soil structure stabilized by microbial filaments and exudates binding mineral and organic materials. Farmers in Africa are under pressure to harvest as much from the land as possible with limited input availability. For them, a deeper awareness of soil microbiome activity would inform strategies to improve crop yields today without jeopardizing soil heath in the future.
I study how conservation agricultural practices affect the soil microbiome and overall soil microbial activity. Considering soil microbiome indicators in evaluating agricultural sustainability can help farmers minimize the risks they take when adapting new practices to maintain and restore soil health and organic matter.
Soil: more than just dirt. 😉
Note: this is a slightly extended transcript of a two-minute “lightning talk” given by Nina Camillone at the fourth annual Penn State Microbiome Center Networking Event on October 1, 2019 in University Park, PA.
Confessions of a Stranger 