Effects of fall tillage on topsoil loss
A common belief is that topsoil only erodes in the spring, during the growing-season or maybe in the fall. However, much wind-related soil erosion happens in the winter and is a direct result of fall tillage.
Fall Tillage
Tillage loosens soil that would otherwise be held together by crop roots and fall volunteer crop growth, even if no cover crop is planted.
If fall tillage is not performed, be sure to leave stubble as tall as possible for all crops and spread remaining crop residue evenly across the field during harvest. Crop stubble can capture snowfall and reduce or eliminate wind soil erosion. Crop residue will more likely stay in the field, allowing residue decomposition and nutrient cycling to stay in the field instead blowing away.
If a living cover crop is left in the field in the fall, plants can remove water from the soil and help dry it out for spring planting.
Avoiding fall tillage and performing spring tillage as needed may not be a perfect system from a soil health perspective, however, it would be a step in the right direction to minimize topsoil blowing in the winter.
After corn harvest, if corn stalks are short and a mat of corn residue remains flat on the soil surface, tillage may be warranted. When corn residue is thick and close to the soil surface, soil moisture may become trapped in the spring and delay planting. In this circumstance, using a disk chisel to cut corn residue into smaller pieces and bury a portion of the corn residue may be helpful. Larger soil clods from chisel shanks should not allow as much soil erosion and will help maintain corn residue on the field. Aggressive tillage will leave bare soil, and shallow vertical tillage may cause much of the corn residue to blow away.
Topsoil blowing from fall tilled fields either blows far away or is deposited in ditches or shelter belts next to the fields. Winter-blown soil results in black-colored fields and roadside ditches, whereas fall non-tilled fields and the ditches next to them remain white.
Weed Control
When not conducting fall tillage, herbicides likely will need applied to control winter annual and perennial weeds present in a field, particularly foxtail barley. No type of fall tillage can control foxtail barley. Only a glyphosate application at 1.5 pounds acid equivalent per acre this fall will provide the most effective foxtail barley control. If herbicide-resistant horseweed like marestail is present in a field right now, apply 2,4-D ester at least at 0.75 pounds acid equivalent per acre. If residual herbicides are applied in the fall to control summer annual weeds the next growing season, spring tillage will reduce herbicide effectiveness in the spring. Apply residual herbicides in the fall when soil temperatures stay below 50 degrees Fahrenheit.
Nutrient Cost of Lost Topsoil
NDSU research in 2025 (“What is the Worth of an Inch of Topsoil,” Naeem Kalwar, NDSU Langdon REC) determined topsoil loss in the winter of 2024-25 resulted in nutrient losses costing $6,682.95 per acre to replace only five nutrients of the ten that were lost based on applying commercial fertilizer for a 0-6 inch deep soil sample per acre at 2025 fertilizer prices. Based upon this information, nutrient loss with every inch of topsoil per acre costs $1,113.81 to replace the five nutrients.
Based upon this information, farmers are better off not tilling soils after harvest and letting volunteer crop plants thrive. Crop stubble will hold the topsoil together and capture more snow for improved soil moisture availability for 2027 crops. Volunteer crop growth will add organic material to the soils.
Our gratitude is expressed to Naeem Kalwar, Soil Health Specialist at the NDSU Langdon REC, for his research and insight on soil health, especially his recent article, “Farmers can retain topsoil by skipping fall tillage.”
Jeff Stachler, Ph. D., C.C.A.
Jeff.Stachler@ndsu.edu
Extension Cropping Systems Specialist
