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THE FOURTH PRINCIPLE OF SOIL HEALTH

Living Roots as Often as Possible

The past 150 years of conventional farming has been very
extractive and destructive to our soils, with extensive loss Photo by David Kleinschmidt
of both topsoil and soil organic matter. To be able to re-
generate our soils, we must first identify what our resource
goals are for that field. It might be to build more carbon,
reduce erosion, increase infiltration rates, supplement
livestock feed, cycle nutrients, provide a nitrogen source
for the next crop, increase mycorrhizal fungi, etc… What-
ever that resource concern is, it must be addressed with
a living root that will feed the soil microbes through car-
bon-rich root exudates.

However, when crop rota-
tions consist of only annual
monocultures, the soil and Many farmers are finding new ways to work with nature
the microbes are only being and the complexity of plant collaboration by interseeding
fed for 3-4 months out of the cover crops into standing cash crops. These cover crops are
year. Limited living roots and designed to not compete with the cash crop but they act as
very little diversity leads to a a trade-off of nutrients as the mycorrhizal hyphae connect
minimal amount of biological to different plant species. As one plant is naturally senesc-
activity and diversity, which ing, the next cover crop is right there to take off and keep
causes our soils to be weak and the carbon pump primed and to keep the nutrients cycling.
anemic. Living roots “trade” This “Catch and Release” method, as Jeremy Wilson refers
Photo by Jimmy Emmons Plant root exudates leaking out exudates to soil microbes in are taken up and made available to the next crop, part of the
to it, ensures that the nutrients mineralized from one crop
or “sell” their carbon-rich root
nutrient cycle. This helps to ensure that nutrients stay on
exchange for plant nutrients
the fields they are in and out of the watersheds where they
that are being made available
to feed soil biology.
through biological processes.
stream who rely on that water source for municipalities and
This basic economy forms stable soil aggregate structures can become a toxic problem to many communities down-
that increase soil infiltration and water holding capacity as fishing industries.
well as create a habitat for the microbes to live on as they
move around in films of water in the soil. Improved soil
structure also aids in the soil’s inhalation of oxygen which is Photo by Brett Peshek
critical for microbes to survive.
Oxygen, food, water, and shelter: things that all living crea-
tures, including soil microbes, need to survive. Healthy
soils can provide all of these but it all starts with living plant
roots! Cover crops are essential in this cycle of life as they
maintain a carbon flow in the “off season” of our cash crops.
The more diverse and complex the cover crops are, the
more diverse root exudates are produced, feeding more of
a diverse community of microbes in the soil. More is better
than less but something is better than nothing, so don’t be
afraid to plant a very basic cover crop like cereal rye if it is By David Kleinschmidt • Mulberry Grove, IL
late in the growing season and that is the only thing that David Kleinschmidt is an Independent Soil Health
makes sense to use – it will still give a great carbon boost to Crop Consultant from Illinois as well as a contract
the soil’s biological life! consultant with Understanding Ag, LLC.

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