Maximizing Biodiversity

Part four in our mini-series on the soil health principles by Mark J. Kopecky, New Mexico State Agronomist,
United States Dept. of Agriculture/ Natural Resources Conservation Service (USDA/NRCS)

“Maximizing Biodiversity” is the complement to “Maximizing Roots” in the half of the circle pictured in the diagram below that’s focused on feeding the soil. In the previous blog post we covered a few of the important points about roots and why we need to have a diversity of living roots in the soil for as much of the year as possible. It seems pretty obvious, but achieving that diversity in roots requires a diversity of plant species.

You might already be familiar with the illustration below from the Soil Biology Primer, picturing the soil food web. We know that there are more living organisms in a single spoonful of soil than there are people on earth, and we’re learning more all the time about how important these organisms are in maintaining a healthy soil:

In the previous article, we covered several of the biological processes that happen underground in association with plant roots and why these are important for soil health. The diversity of plants we need for maximizing living roots also translates to maximizing above-ground biodiversity, and this above-ground component is also important for achieving the healthiest soil.

Maximizing biodiversity starts with maximizing the species of plants in an area. We focus on the specific area of our cropland, pasture, or rangeland, but this principle extends to neighboring areas like windbreaks, fencerows, buffer strips, and neighboring wild land as well. Maximizing the diversity of plant species in and near the focus area maximizes the total range of organisms available in addition to microbes– earthworms, mites, spiders, insects, birds, and many others. All of these have jobs to do in keeping the soil and cropping system healthy: shredders, decomposers, pollinators, predators, seed eaters and seed dispersers, soil engineers, and so on. And while plant parasites, pathogens, and other crop-destroying agents are also part of this system, maximizing biodiversity gives us the best chance at controlling these problems with a minimum of intervention.

This takes us all the way around the “soil health circle”. I hope this review of the four basic principles of managing for healthy soils has been a good refresher for you. If you’re interested in learning more about how a whole farming or ranching system can work together to achieve the most benefits from maximizing biodiversity, I recommend the late Jerry Brunetti’s book The Farm as Ecosystem.

Next, I will describe how a fifth principle, Integrating Livestock, can help us take soil health to an even higher level.

Explore the next principle of soil health!