Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/15/2008
Publication Date: 1/28/2008
Citation: Anderson, R.L. 2008. A new approach to weed management, based on population dynamics. No-Till on the Plains Conference, Salina KS, January 29-30, 2008. pp.36-43. Interpretive Summary: Rotations are rapidly changing the Great Plains because of no-till systems. Weed management is also changing because of crop diversity. Producers can now manage weeds with less herbicides because more opportunities exist to disrupt population growth of weeds. Designing rotations to include two cool-season crops followed by two-warm season crops and maintaining weed seeds on the soil surface are especially effective in reducing weed densities in producers’ fields. Weeds can be controlled with 50% less costs because weed densities are so low compared with conventional rotations based on tillage.
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 Central 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 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.