Healthy soil is one that has good soil life, fertility, and structure. To build and maintain healthy soil, we need to practice the soil health principle of minimising soil disturbances.
Physical soil disturbances are a well-documented and well-understood concept; however, we underestimate the disturbances that result from chemical and biological processes.
These disturbances take place in the soil when we bring in excessive nutrients. This can be through over-fertilization, excessive feeding, and over-application of pesticides. Each of these in the right context and used at the correct rates are beneficial, but as soon as there is an excess it causes problems. Chemical disturbances dismantle the symbiotic relationship that exists between our fungi, bacteria, and plant roots in the soil. In turn, we disrupt our entire soil food web and its associated functions in the soil.
Biological disturbances are brought about by practices of overgrazing and leaving soils bare for extended periods. These biological disturbances remove the ability of plants to photosynthesize and pump carbon back into the soil (where it belongs), decrease root growth and decrease root exudates. These processes are important for building a good soil structure and a healthy microbial community.
Tillage practices cause physical disturbances in soils. Tillage breaks up well-formed soil aggregates and forms compacted bare soil with poor infiltration rates that are susceptible to erosion. Tillage also mixes excess oxygen with organic matter (carbon) from the soil which results in carbon being lost from the soil and carbon dioxide being emitted to the atmosphere.
As stewards of the soil, it is our responsibility to limit soil disturbance, whether it be a chemical, biological, or physical disturbance. Instead of working against the soil and her friends (soil food web), lets rather work with them and they will reward us!
Fuhrer J. Soil Health: Principle 2 of 5 – Minimizing Soil Disturbance.