Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2007
Publication Date: 1/16/2008
Citation: Anderson, R.L. 2008. Crop diversity and no-till: keys to pest management in the U.S. Great Plains. Weed Science. 56:141-145. Interpretive Summary: Crop rotations have changed in the semiarid Great Plains because of no-till. Producers are now growing a diversity of crops along with winter wheat and fallow. This change to crop diversity has enabled producers to expand their opportunities with cultural tactics for weed control. With a weed management system based on disrupting weed population dynamics, producers in the Central Great Plains have reduced cost of weed management 50%. Furthermore, they are able to grow some crops without herbicides; weed density is so low that crop yield is not affected by weed interference. Crop diversity has also reduced root diseases such that crop yield during favorable climatic conditions is doubled. Net returns are greater with no-till rotations and crop diversity.
Technical Abstract: No-till systems and crop residue management have changed cropping systems in the Central Great Plains. Previously, winter wheat-fallow was the prevalent rotation; now producers grow warm-season crops along with winter wheat and fallow. With this diversity of crops, producers have developed a multi-tactic approach to weed management where cultural tactics disrupt weed population growth. Producers using this approach are managing weeds with 50% less cost compared with the winter wheat-fallow rotation. Two key components of the multi-tactic approach are arranging cool- and warm-season crops in a cycle of four and using no-till practices. The cycle-of-four rotation also minimizes severity of plant diseases, thereby increasing yield potential of crops. Net returns are fourfold greater with crop diversity and no-till compared with winter wheat-fallow and tillage. Reduced cost with weed management comprised one half of the gain in net returns with no-till rotations and crop diversity.