Approaches to tillage have little effect on whether fields have high weed populations.
After examining weed population data in 2,046 Saskatchewan fields and correlating it with 1,010 farming practice surveys, Gord Thomas of Agriculture Canada in Saskatoon said the number of weeds in a field doesn’t relate to the type of tillage.
“It appears that weed management approaches make the difference between whether you have economically significant levels of weeds or not,” he said addressing the 20th annual Saskatchewan Soil Conservation Association conference in Regina Feb. 12.
Whether a farmer disked a crop into a fall-tilled field or knifed it into a stand of tall stubble made little difference when it came to the number of weeds.
Read Also
VIDEO: Green Lightning and Nytro Ag win sustainability innovation award
Nytro Ag Corp and Green Lightning recieved an innovation award at Ag in Motion 2025 for the Green Lightning Nitrogen Machine, which converts atmospheric nitrogen into a plant-usable form.
However, the type of weed that is dominant in the field could depend on tillage.
“We did see some examples of extremely high weed counts in both reduced tillage and high tillage systems. In the case of the high tillage systems, this can be attributed to a lack of herbicide used. In reduced tillage it may have been from herbicide failure due to timing,” he said.
The top three most abundant species of weeds in all tillage systems were green foxtail, wild oats and buckwheat.
“We did see more volunteer flax and canola in the systems that didn’t rely on soil disturbance. But this was likely to the use of these oilseeds in rotations that might not have been used in high-tillage systems,” he said.
Narrow-leaved hawk’s beard and foxtail barley were also found more often and in higher densities in reduced tillage fields than in those where the soil was tilled.
In high tillage systems, weed species such as wild mustard, perennial sow thistle, cow cockle and bluebur were more common than in reduced tillage regimes.
“In short we found that early weed control is critical in all systems. In direct-seeded systems the green foxtail, wild oats and wild buckwheat remain the biggest threats,” he said.
