With herbicide resistance on the rise, more farmers are making tillage the foundation of their integrated weed management program. But new research shows that when tillage occurs can make a big difference in how effective that tillage will be.
In a study featured in the most recent edition of Weed Science, a team of researchers tilled four fields every two weeks during the growing season. They then monitored each site to quantify the density and species of seedlings that emerged from the weed seed bank six weeks after each till. They found that total weed density tended to be greatest when soil was tilled early in the growing season. More than 50 percent fewer weeds emerged after late-season tillage.
Tillage timing also made a difference in the composition of the weed communities emerging from the weed seed bank in the test fields. After early-season tillage, some species clearly dominated. After late-season tillage, the distribution among the various weed species tended to be much more even.
What does this mean for growers? The research team says farmers may be able to mitigate the impact of weeds on crop yields by adjusting the timing of their tillage, crop rotation and other cultural management practices.
Want to know more? The full text of the article “Timing of Tillage as a Driver of Weed Communities” is now available in Weed Science Vol. 65, Issue 4, July 2017.