Root cutters: perennial weed control with low risk of soil erosion

Perennial weeds are difficult to control due to their underground root parts, which usually require repeated intensive tillage (e.g. multiple harrowing and ploughing) or systemic herbicides (e.g. glyphosate/Round-up) to control. This type of tillage often leads to long periods of bare soil that has a high risk of soil erosion and nutrient leaching. Perennial weeds are thus a major obstacle to the EU's goal in Farm to Fork to both reduce pesticides by 50% and nutrient leaching by 50%. 

In  a new article that has been posted as a pre-print (i.e. before it has been scientifically reviewed), we have evaluated the newly developed horizontal and vertical root cutters. The experiments show that the root cutters, in particular the horizontal root cutter, can have a better or equally good effect against several different perennial weeds (creeping thistle, couch grass and perennial sow-thistle) as more intensive tillage such as disc harrowing, stubble harrowing and rotor tillering, but that the horizontal cutter, unlike harrowing, does not increase the risk of soil erosion or nutrient leaching. 

An article from  the ACDC-weeds project has also recently published an article where they tested the horizontal cutter with and without ploughing and with and without cover crops. It shows that even though ploughing generally has the best effect against perennial weeds, the horizontal cutter has a surprisingly good effect on its own and when combined with cover crops, you can often achieve comparable results to ploughing. 

Taken together, these results show very good potential of root cutters to control perennial weeds in many different agricultural systems: significantly reducing tillage in organic farming and potentially reducing herbicide use in systems that do not use ploughing but instead depend on herbicides to control perennial weeds such as conservation agriculture and regenerative agriculture. The fact that root cutters can be combined with cover crops gives them an enormous potential to be used to develop more sustainable cultivation systems that minimize soil erosion, nutrient leaching and herbicide use.