Title: Managing weeds with a population-based approach Author
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 28, 2013
Publication Date: January 28, 2013
Citation: Anderson, R.L. 2013. Managing weeds with a population-based approach. Canada FarmTech Conference Proceedings, Edmonton ALB, January 29-31, 2013. Available: http://farmtechconference.com/speaker-profile/randy-anderson/ Interpretive Summary: The adoption of no-till has led producers to consider more crop diversity in their rotations. This change in system design led to a management program based on strategies that disrupt weed population dynamics and reduces the need for herbicides. Producers using population-based management are controlling weeds with 50% less inputs. Weed density in producer fields are declining across time, subsequently reducing the need for herbicide use even more. The approach includes various cultural strategies such rotation design, no-till, varied crop planting dates, crop residue preservation on the soil surface, and competitive crop canopies to reduce weed seed production.
Technical Abstract: No-till cropping systems are improving precipitation-use-efficiency, increasing land productivity, and restoring soil health in semiarid regions of the world. However, weed resistance, rising costs, and concern about environmental impacts are stimulating questions about the extensive reliance on herbicides with no-till. Scientists and producers are seeking a broader perspective with weed management. One approach is disrupting weed population growth with cultural tactics, thus supplementing herbicides in controlling weeds. This paper describes a successful system based on this approach in the semiarid steppe of the United States that controls weeds with 50% less inputs, reduces need for herbicides, and increases net returns for producers. Two key components of this approach are rotation design and no-till. Rotations comprised of crops with different life cycles, such as cool-season and warm-season crops, suppress weed population growth. No-till improves crop growth by its favorable impact on water relations and weed management by its detrimental impact on weed seed survival in soil. In addition, cultural tactics improve crop competitiveness to reduce weed seed production. We encourage scientists in semiarid regions to integrate weed management with design of crop rotations, and also to consider crop diversity in regards to other aspects of crop production.