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BIOLOGICAL INDUCTION IN THE PLANT-SOIL MICROBIOME

It comes as a surprise to many to learn that plants and mi- The answer is—more plants!! Or more correctly, a greater
crobes constitute 99% of the biomass of life on earth. Things diversity of plants, growing together in communities.
we can readily observe, like people, animals, birds, reptiles, We need to be mindful that in the not-too-distant past, the
insects, and fish, make up the remaining 1%. world’s prairies, grasslands, savannas, and meadows were ex-
Collectively and cooperatively, plants and their associated tremely diverse, with 300 to 500 plant species thriving togeth-
microbes underpin the functioning of all major ecosystems, er in mixed communities. At least 60% of the species were
including soils. Improving our understanding of these in- forbs. Plant diversity increases microbial diversity, assisting
teractions is key to restoring the productivity and resilience the sequestration of soil carbon, which in turn improves soil
of agricultural land, enhancing the quality of the food and health, enhances the availability of nitrogen and phosphorus,
fiber produced, reducing the need for inputs, increasing improves soil water-holding capacity and water-use efficien-
farm profit and supporting human health and wellbeing. cy and enhances plant productivity. These beneficial effects
Although the biomass and are additive and every kind of plant counts—the more differ-
power of microbes is im- ent types of plants you put together, the better it gets.
mense, like all other life
forms they require an energy Photo by Christine Jones
source. For most microbes
Photo by Doug Garrison of agricultural significance,

this energy comes from the
sun. The liquid carbon path-

of green, actively photo-
Root hairs and the fungal network of a way requiring the presence
corn root that will feed the microbes in synthesizing plants is the
the surrounding rhizosphere.
principal means by which
light energy is transformed to biochemical energy and Jim Harbach (top), Schrack Farms, Loganton, PA, watches as Peter Donovan per-
transported to the soil ecosystem. Within soil, some of the forms a water infiltration test in a multi-species cover including buckwheat, sun-
liquid carbon is distributed via common mycelial networks, flowers. sorghum, forage collards, non GMO soybeans, Persian clover, radish, canola,
linking plant roots with distant microbial communities and subterranean clover. Infiltration rates are very high due to the diverse cover mix.
while the remainder supports trillions of microbes in the Fortunately, it is not necessary to restore several hundred
rhizosphere. Some intriguing symbiotic relationships take species of plants to agricultural land to achieve soil health
place here, including microbivory, or rhizophagy, in which benefits. Relatively simple cover crop mixes can go a long
microbes are attracted to and engulfed by actively growing way toward improving soil function, provided there is a di-
root tips. After being stripped of their nutrient loads, mi- versity of plant functional groups. It is beneficial if diverse
crobes exit via root hairs to start the cycle again. cover crop and forage crop plantings can be accompanied by
Some forms of microbes are also able to freely alternate a biostimulant, preferably on the seed, but at the very least
between a soil phase and an endophytic (inside the plant) in furrow or as a foliar applied at or soon after emergence.
phase. These beneficial microbes can assist with the trans- High analysis fertilisers disrupt the plant-soil microbiome
fer and assimilation of nutrients, confer pest and disease and should not be placed on, under, or near seeds - or indeed,
resistance and improve tolerance to abiotic stresses such in contact with the soil. Other harsh chemicals, such as her-
as frost, drought and salinity. The movement of microbes bicides, insecticides, and fungicides also disrupt the intricate
from the soil into plant roots (and from there into stems, relationships that exist between plants and microbes.
leaves, flowers and seeds) is termed biological induction. Remember, the soil is a living thing. Our quality of life de-
Common mycorrhizal networks, microbivory and biologi- pends on how well it functions.
cal induction are but a few of the extraordinary symbiotic By Christine Jones, Ph. D
relationships that exist between plants and microbes. Many A native of Australia, Christine has rapidly become one of
more are yet to be discovered. The question then becomes— the most sought after Soil Health speakers in the world and
how do we increase the number and biomass of the bene- has been wildly popular on the United States Soil Health
speaking circuit. We count it a blessing to call her a mentor
ficial microbes that are able to assist the growth of plants? and a good friend of Green Cover Seed.
For further information, visit www.amazingcarbon.com.

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