I believe that at some point in history, we will fully appreciate and understand that healthy soil is our greatest competitive advantage and the most valuable asset on Earth.
As agriculture is the foundation of all civilization, we cannot ignore the evolution of food production. We have gone from gathering food to industrialized agriculture and now are looking down at the property of soil in our future.
To fully appreciate the role soil plays in our lives, we must prepare to unearth her secrets and shift our lofty perspective. Most folks, including farmers, look at the top of the ground or the top of the topsoil and amend it according to their needs. And although our environmental footprint in agriculture is very low compared to other industries, we continue to just maintain or deplete soil rather than feed it.
To fully appreciate the property of soil, we must dig below the surface.
Plant matter, the stuff we see, covers the soil thus keeping it cool. This trash becomes humus which is where carbon converted into CO2 and with sunlight is synthesized as sugar in the plants. This feeds the plants and wards off pests. As the plant matures, the sugars go back down into the soil, feeding the microbes, and the biological process is repeated.
It has been said there are more micro-organisms in a spoon of healthy soil than there are human beings on Earth. These micro-organisms feed on organic matter, producing nutrients which are taken up by the plant.
When there is an imbalance, such as a shortage of CO2, the soil is bound, so to speak, and can’t take on extra responsibility. For example, if CO2 is not present in abundance, then nitrogen cannot be metabolized. Adding extra N does not build soil — it is the CO2 that is needed by the plant to metabolize the nutrients, convert to sugar and feed it. The plant will draw that from both the soil and from the air where it is sequestered through the leaves.
- More with Brenda Schoepp on the Alberta Farmer: Asking the questions that need to be asked
Nutrient deposit is visible when you look at soil in a cross-section. The entry point of an earthworm will be darker, regardless of the depth, as this is an indication of nutrients. The root of a brassica, such as radish, will be long and strong when the plant has a balanced nutritional profile based on CO2. The question is: In times of extreme growth, will the plant have enough CO2 to meet its nutritional needs as the metabolism of all other nutrients is dependent on this?
It is argued that as we clear land and fail to leave material for humus, we can deplete the soil to the point where amending the surface will no longer be viable. The practices of no-till seeding and rotational grazing are used by farmers to ensure there is always enough humus decaying to produce CO2.
Most of our annual plants are progeny of perennial plants that had time on their side to guard the humus, grow the roots, and remain in production for long periods of time. Plant breeding has asked these same species to perform the equivalency in a short period of time as annuals without the advantage of allowing the soil to work through the process and “store” the carbon needed. The result is a marathon of actions to entice the soil to perform without understanding the cycle of life beneath the surface.
The primary requirement of all plants is CO2 because without it no sugars are formed. There is not enough CO2 in the air to support intensive food production, so it needs to also be pulled up from the soil. Trees and grasslands are fabulous sequesters because they have a relatively uninterrupted life cycle, farmed crops and heavily grazed lands need extra support.
The whole respiration process can be viewed in a human analogy. When you have asthma there is a shortage of vital oxygen which feeds the body and the brain. It is important to safeguard against respiratory distress. Plants and soil respire, and we must safeguard against respiratory distress by ensuring that carbon is both captured and created.
Experts put the visual of good soil into perspective saying it should look like black cottage cheese. They also remind us to work with the adaptability of soil in our management practices. A good example is the use of herbicides. The treatment of the same weed in the same field at the same time can only result in resistance — which is a natural response. Rotation and the inclusion of competitor plants is a cost-effective and healthy alternative. (To learn much more about soil health, attend the Western Canada Conference on Soil Health in Edmonton early December.)
As we look ahead in agriculture and the challenge of feeding so many, we may want to unearth the beauty of soil — and consider that nutrient density is our destination and will never be an accidental outcome.
For me, the driving reason to understand soil is to understand ourselves and our relationship between healthy soil, healthy plants and healthy bodies. This is soil’s greatest secret and she has held it deep in her heart, waiting for us to rediscover the foundation of all life.