Copyright © Graeme Finn
soil organic matter is the house microbes live in. water extractable organic carbon is the food they eat.
While not readily identified, factors affecting biological activity in soil (moisture, carbon availability, temperature, pH, etc.) are useful when measuring soil health.
A myriad of organisms live in soil, some of which perform beneficial functions such as organic matter decomposition and nutrient cycling, whilst others are associated with plant disease. Some of these organisms are visible to the naked eye (earthworms, mites, insects, etc.), but most are microscopic (fungi, bacteria).
A healthy soil is not only fertile, but productive. Weeds, subsoil constraints, diseases, and climates limit plant growth and productivity even when soil is fertile. It is necessary to recognize that the yield of a plant is limited by a deficiency of any one essential element, even if all others are present in adequate amount.
Our primary objectives in obtaining balance in soil fertility are to ensure nutrient storage capacity is maintained, soil fertility is adequate for designated land usage.
Soil organic matter consists of all materials found in or on soil that originate from organic material - both living and dead organisms in various stages of decay. The living microbes in this pool cycle rapidly and are essential for organic matter decomposition, nutrient cycling, and soil stabilization. This decomposition regulates the flow of energy and nutrients in the soil and plays a key role in improving soil structure.
Agricultural practices influence both the quantity and quality of soil organic matter which in turn directly impact soil productivity and stress recovery. The amount of organic matter in a soil is often used as an indicator of the potential sustainability of a system and is thus required when developing farming systems.
Understanding Soil Biology
Balancing Soil Fertility
If soil health is the goal, crop diversity cannot be ignored nor overstated. While they offer a balanced 'diet' for soil biology, balanced and diverse ecosystems are also best for plant resilience and growth.
Soil health increases organic matter and soil fertility while also allowing for supplemental grazing, erosion control, deep root growth, nitrogen cycling, and weed suppression.
The keys to achieving a healthy soil include minimizing mechanical disturbance, increasing plant diversity, living roots as long as possible, and properly integrating livestock onto the cropland.
Maintaining the Soil Organic Matter Equilibrium