Minimizing Disturbance

Part two in our mini-series on the soil health principles by Mark J. Kopecky, New Mexico State Agronomist,
United States Dept. of Agriculture/ Natural Resources Conservation Service (USDA/NRCS).

“Minimizing Disturbance” is the complement to “Maximizing Soil Cover” in the half of the circle that illustrates the concept of protecting the soil. While cover works from the surface of the soil, minimizing disturbance helps to promote and protect the inner workings of the soil. 

Agriculture itself is sometimes referred to as “disturbance ecology,” because to grow most of our food and fiber crops, we need to alter the natural soil environment through disturbance of some sort. Some of the disturbances we want to minimize are:

• Physical (tillage, which destroys soil aggregates and disrupts the whole soil foodweb; and compaction, which also destroys aggregates and reduces porosity),
• Chemical (excessive or inappropriate fertilizer or pesticide applications, which disrupt soil biology and lead to plants “learning” to depend on external inputs rather than relying on soil biology), and
• Biological (disrupting the natural soil foodweb by biological “shocks” like overgrazing, monocropping, and other disturbances that alter the natural balance of organisms in the soil and lead to insect and pathogen problems).

By minimizing disturbance, we help protect the soil to promote healthy internal soil characteristics that go hand in hand with maximizing cover:

• Increasing the infiltration of both air and water—by maintaining stable aggregates and their associated macropores.
• Storing as much water as possible for plants and the other organisms in the soil foodweb while still allowing an overall aerobic soil environment –this helps plant roots to thrive in conjunction with the microbial life that helps to nourish and protect the crops we grow.
• Providing habitat and “highways” for underground soil organisms like bacteria, protozoans, fungi, earthworms, and others.