Location: Integrated Cropping Systems ResearchTitle: Underseeding clovers in small grains to suppress weeds in organic farming
Submitted to: Western Society of Weed Science Research Reports
Publication Type: Research Notes
Publication Acceptance Date: 1/3/2017
Publication Date: 3/13/2017
Citation: Anderson, R.L. 2017. Underseeding clovers in small grains to suppress weeds in organic farming. Western Society of Weed Science 2017 Research Reports, pp. 56-67.
Interpretive Summary: Organic producers are interested in no-till systems, but they are concerned about controlling weeds without tillage. One possible option to reduce tillage is to interseed annual clovers into winter wheat. Clover growth after winter wheat harvest can suppress weed growth such that weed seed production in the fall is almost eliminated. This study identified 2 annual clovers that are suited for interseeding into small grains in this region. If the clovers die by winterkill, no control tactics will be needed the following year before planting the next crop. Berseem clover appears to be especially suitable for interseeding into small grains because it winterkills. If successful, interseeding will help producers reduce tillage in organic farming, and to start restoring the health of their soil.
Technical Abstract: Organic producers are seeking alternative tactics for weed control so that they can reduce their need for tillage. In this study, we examined the impact of underseeding clovers into small grains to control weeds after harvest. Also, if the clovers winterkill, then control actions would not be needed to kill volunteer clovers the following year. The clovers were planted early in the spring in both winter wheat and oat. Clovers effectively controlled weeds after harvest, but red clover and crimson clover survived the winter and infested the following crop. Berseem clover readily winterkilled but also was injured by spring frost. Delaying berseem clover planting until early May avoided frost damage. Berseem clover may offer organic producers a viable option to control weeds after small grain harvest without needing to till.