Editor’s Note: Jay Fuhrer, retired NRCS soil health specialist and conservationist at the Menoken Farm demonstration farm in Menoken, N.D., wrote the 5 principles of soil health. In this series, Fuhrer explains each principle and provides an on-farm example of the theory in practice. In the third installment of this series, Fuhrer examines soil health principle 3: plant diversity.

Diversity is the elusive “ Holy Grail” for ecosystem function, always easier to discuss than to achieve. The International Stratigraphic Chart states the first land plants are estimated to have evolved approximately 458 million years ago — with the first microbial communities being much older at 3.48 billion years ago. 

In comparison, homo sapiens are very recent. Plants and microbes have the advantage of biological time

co-existing and supporting each other as one. The plant definition then becomes the plant tissue plus the microbes, which are both inside and outside the plant from the tallest growing point to the last root tip in the soil.

We know plants contain thousands of metabolites, functioning through a primary metabolism and a specialized metabolism, as referenced by Metabolomics in the Rhizosphere: Tapping into Belowground Chemical Communication, which notes that plants “secrete a large array of primary and secondary plant metabolites into the rhizosphere to facilitate interactions with their biotic and abiotic environment.”

Ecosystem processes would have been maximal, as highly diverse grasslands, forests, animals and microbes were building our soils over geological time. Think of energy flow with sunlight always shining on a…