Limited Disturbance
Soil Health: Principle 2 of 5 – Minimizing Soil Disturbance
Soil disturbance comes in three varieties, with each form impacting important soil functions.
Physical Disturbance: The most obvious form of soil disturbance is by tillage. Compared with soils under no-till soil health management, tilled soils have:
- Decreased water infiltration and storage. Tillage destroys soil aggregates and severs natural pathways and pores created by roots, worms and soil biota. When these pathways are broken, precipitation slowly seeps into the soil, often at rates slower than the rate of rainfall. Soil water storage is decreased because the aggregates that create pore space for water to be held are destroyed, and organic matter is reduced. Soil organic matter can hold up to 20 times its weight in water (Reicosky, 2005).
- Reduced organic matter. Tillage destroys organic matter by exposing it to air. When exposed to air, organic matter is consumed by opportunistic bacteria, and lost through erosion.
- Increased Erosion. Water erosion increases because of reduced infiltration rates; and wind erosion increases because tillage leaves less protective residue on the surface.
Biologic Disturbance: While not as visually obvious as a physical disturbance such as tillage, biological disturbance also impacts soil function. All soil life needs energy to survive. That energy is provided by plants. Plants harvest CO2 and sunlight through photosynthesis to produce energy, namely sugars, some of which is transferred via roots to below ground life. A living root in the soil as much as possible is important. Cover crops in your crop rotation are a great way to extend and diversify living root presence. Proper grazing management will also increase the ability of perennial plant to harvest sunlight.
Chemical Disturbance: Chemical disturbance occurs with overuse of fertilizers, herbicides, insecticides and fungicides. A diverse cropping system can help reduce reliance on pesticides and fertilizers.
News & Events
Wet or dry, less stress: Father and son credit focus on healthy soils
Eli (left) and Barry Little. Photo courtesy of USDA-NRCS SD. By Lynn Betts For the South Dakota Soil Health Coalition “We feel like if we get the moisture that God gave us and leave it where it's supposed to be, we can get through most any year,” Barry Little...
Standing up to drought: No-till, cover crops build resilient soil for managing water
By Janelle Atyeo For the South Dakota Soil Health Coalition South Dakota farmers slogged through two wet years before the rain shut off in the middle of the last growing season. Now a warm start to winter without much snow cover has farmers heading into the next crop...
Maximum benefits seen when cover crops and cattle grazing added to no-till
By Lura Roti for South Dakota Soil Health Coalition Driving conditions were challenging as Brandt, S.D., farmer Tyler Brown made his way south to the Texas Panhandle this December. “I started out in a snowstorm, then it became a dirt storm. And it made me realize, we...