Mowing as a Weed Management Technique – Kali Kasper
Tillage is a common practice in organic agriculture systems, leaving soil vulnerable and subject to erosion. Mowing and roller crimping are techniques that can minimize tillage requirements while maintaining soil coverage. Mowing and roller crimping can effectively terminate a cover crop (such as field pea green manure), and compared to tillage, less weed regrowth will occur. A great option for this in Saskatchewan is using wheat the following spring after a field pea green manure crop. Then, using a mowing technique for termination and yields will not sacrficied.5 If mowing is implemented in the crop, especially if a cereal crop is in furrow, it is possible to mow weeds that are above the cereal seedling canopy that are competing for sunlight.6
If mowing is used instead of tillage in a summerfallow system, many weeds will be controlled and some weeds, like Canada Thistle, could possibly be eliminated after three or four passes.6
A detrimental aspect involved in this method is the added step of sanitation, to remove vegetative structures that could possible disperse after a mowing implement. Therefore, burning, burying or transport must involved to exhibit proper removal.6
I see mowing as an important implement to keep in mind instead of immediately turning to tillage as an answer for weed control. Although mowing is more expensive and time consuming, producers must invest in their soil. This means limiting the amount of damage their fields experience and maximizing nutrients that are available to the crop without depleting soil nutrients.
5) Shirtliffe, S. J. 2012. Progress towards no-till organic weed control in western Canada. Renewable Agriculture and Food Systems, 27(1), pp.60-67.
6) Weed Management in Pasture Systems. 2001. The Pennsylvania State University; College of Agricultural Sciences.