Most no-tillers won’t want to hear it, but some University of Nebraska research indicates an occasional limited tillage pass won’t seriously damage no-till’s favorable soil structure. But with herbicide costs increasing significantly this year, we’ve heard that a few no-tillers are thinking of using a light tillage pass as a weed control option.

Don’t Get Me Wrong

I’m not advocating that no-tillers use any tillage. But maybe the consequences of making a single tillage trip across a no-till field isn’t the disaster you might have imagined. 

Charles Wortmann, a Nebraska soil and nutrient management specialist, says occasional tillage in a no-tilled field needs to deal with a specific objective. This could include controlling weeds, fracturing a soil compaction layer, incorporating lime or manure, reducing the vertical stratification of nutrient availability, eliminating ruts, increasing soil organic matter to a greater depth and dealing with heavy crop residue accumulation. 

Even so, he doesn’t recommend occasional tillage more than once every 5-10 years. This is based on several 5-year studies that compared five occasional tillage practices under no-till conditions.

An early concern among the researchers was that the many benefits to soil properties and productivity gained from continuous no-till would be lost with a tillage trip. Wortmann says the studies indicate any negative effects normally last less than 1 year. However, growers must also weigh the tillage cost and the increased risk of erosion until a crop canopy or residue cover is reestablished.

Yield Impact

Based on 35 trials where occasional tillage was…