Soil is the foundation for everything we’ve built — all agriculture and civilization must grow from healthy soils. And we’re heading straight for some hard limits, beyond which soils will no longer support us. Or, as UC Berkeley soil scientist Ronald Amundson and his colleagues put it in this paper, “Soil is the living epidermis of the planet.”
Soil helps regulate the carbon and water cycles — it’s a reservoir for both cycles, buffering them from shocks and feeding us, all at the same time. But, Amundson et al. warn:
Profound changes are on the horizon for these interconnected functions — particularly sparked by changes to climate and food production — that will likely reverberate through society this century. Ultimately, the way in which we directly and indirectly manage our planet’s soil will be interwoven within our future success as a species.
We are already running into a hard limit when it comes to soil nutrients. Plants need nutrients like phosphorus, nitrogen, and potassium to grow. Microbes, certain plants, and human factories can pull nitrogen out of the air (there’s plenty of it in the atmosphere), but the other nutrients have to come either from mining or recycling.
http://grist.org/food/the-next-big-war-might-be-over-phosphorus/
Brown Administration Launches Healthy Soils Initiative:
http://www.cdfa.ca.gov/EnvironmentalStewardship/HealthySoils.html