Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/11/2014
Publication Date: 2/18/2015
Citation: Anderson, R.L. 2015. Managing weeds with a population dynamics approach. Proceedings from Farming the Margins workshop, Garden City KS, February 18, 2015, pp. 16-25.
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 weed management program based on strategies that disrupt weed population dynamics and reduces the need for herbicides. Producers using this program are controlling weeds with 50% less cost. 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 crop diversity in rotations, no-till, varied crop planting dates, and competitive crop canopies to reduce weed seed production.
Technical Abstract: No-till cropping systems are increasing land productivity. A critical aspect of no-till is controlling weeds. Herbicides are a crucial tool for weed management, but weed resistance is decreasing control efficacy and increasing input costs. 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 U.S Great Plains 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 weed management by its detrimental impact on weed seed survival in soil. In addition, cultural tactics improve crop competitiveness to reduce weed seed production. In some rotations, producers have eliminated herbicide use in 3 crops out of a 4-crop rotation.