Limiting Soil Disturbance Promotes Healthy Soil Structure
This is part three of our five-part Farm Gate series on soil—the foundation of our sustainable future.
Our last article in our soil health series looked at why keeping soil covered by planting cover crops and reducing tillage protects soil from wind and rain erosion. Practicing no-till farming or gardening and cover cropping also reduces soil disturbance, which supports healthy plant growth. Here’s why.
From the surface, there are two things that may not seem obvious about healthy soils. First, healthy soils are full of life. Various species of beneficial bacteria, fungi, nematodes, protozoa, arthropods and others are hard at work underground. They move and stick soil particles together in their efforts to build their homes and lead their best lives.
Soil organism activity builds soil structure, which leads us to the second less obvious characteristic about healthy soils: although soil feels firm, only about half is made of solids, like sand, silt, clay and organic material. The other half is air or empty space. This empty space allows water and nutrients to filter into the ground and allows plant roots to grow.
These two things combined—soil organism activity and balanced soil composition—is what defines healthy soil structure.
Tilling, vehicle traffic or livestock grazing when soil is wet can compact soils and damage soil structure. Compaction collapses soil structure. It breaks apart clumped soil particles and fills in empty space. Compaction limits water infiltration and groundwater recharge, restricts plant root growth and nutrient availability, and increases the risk of surface runoff, erosion and flooding.
Luckily, soil organisms are resilient. Changing land management practices to disturb soil less will give soil organisms the chance to rebuild healthy soil structure and provide plants the conditions they need to thrive.