One of the most effective weed control strategies, but is often overlooked, is cultural weed control. This method is often the most economical form of weed control because it can be as simple as adjusting practices that are already in place.
In my opinion, six of the most common approaches include using
- narrower rows
- higher seeding rates
- taller cultivars
- effective fertilizer placement
- precise planting dates
- dynamic crop rotations
The goal is to achieve crop canopy quickly; making the crop more competitive against weeds. This can be achieved by using narrow rows, higher seeding rates and taller, more robust cultivars. Other ways to make the crop more competitive is to place the fertilizer where the crop can use it and the weeds cannot. Knowing the weed history of a field is vital, so a comprehensive weed control strategy can be made prior to planting. Utilizing an effective burn down and residual herbicide program to keep weeds from emerging should be the primary goal. This is typically more effective than relying solely on an in season treatment.
Probably the most valuable cultural control system is using a crop rotation that includes winter annual crops, summer annual crops, monocots (such as corn) and dicots (such as soybeans). Crop rotation also allows for varying row spacing, seeding rates, planting dates and cultivar heights.
Using all, or some of these strategies will provide an improved weed control system, that when paired with mechanical, biological and chemical weed control practices, will lessen the yield impact weeds can have. Visit with your Crop Quest Agronomist to talk about the best way to get a complete weed control system implemented on your farm.
Written by: Jacob Glavin, 2015 Intern in Precision Ag Division, Kansas State University