Author
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Davis, Adam |
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Submitted to: Weed Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/23/2010 Publication Date: 7/1/2010 Citation: Davis, A.S. 2010. Cover Crop Roller-Crimper Contributes to Weed Management in No-Till Soybean. Weed Science. 58(3):300-309. Interpretive Summary: Cover crops can aid weed management by blocking light and creating a physical barrier to weed seedling emergence. Within no-till soybean production systems, cover crops are typically killed with herbicides prior to soybean planting. Recent advances in cover crop roller-crimper design offer the possibility of physical termination of cover crops without tillage, which may be useful to both organic growers and those who wish to reduce their reliance upon herbicides. A field study within a no-till soybean production system was conducted in Urbana, IL, from 2004-2007 to test whether terminating a cover crop with a cover crop roller-crimper could provide weed management benefits while maintaining soybean yield. Weed growth within soybean following either a vetch or rye cover crop was reduced by 26 and 56%, respectively, when cover crops were rolled rather than killed chemically. Soybean yield loss due to weed interference was unaffected by cover crop termination method. Use of a roller-crimper to terminate a cover crop preceding no-till soybean results in similar yields to those obtained by chemically terminating the cover crop, but reduces biomass and seed production of weed populations that escape control. Technical Abstract: Termination of cover crops prior to no-till planting of soybean is typically accomplished with a burndown herbicide. Recent advances in cover crop roller-crimper design offer the possibility of physical termination of cover crops without tillage. We hypothesized that 1) cover crop termination with a roller-crimper ('Rolled') reduces weed biomass and seed production following no-till planting of soybean compared to a glyphosate burndown ('Burndown'); 2) yield loss of no-till soybean due to weed interference is lower in a Rolled than a Burndown system; and 3) postemergence glyphosate application rate can be reduced, or eliminated, without reducing soybean yields in a Rolled, but not a Burndown, system. A field study within a no-till soybean production system was conducted in Urbana, IL, from 2004-2007 to test these hypotheses. In a split-split plot design with four replications, ground cover (bare soil, rye or hairy vetch cover crop) was the main plot factor, cover crop termination method (Rolled or Burndown) was the subplot factor, and postemergence glyphosate application rate (0, 1.1 or 2.2 kg a.e. ha-1) was the sub-subplot factor. Biomass of residual weed populations within soybean following either vetch or rye was reduced by 26 and 56%, respectively, in the Rolled system compared to the Burndown system (P < 0.001). Soybean yield loss due to weed interference was unaffected by cover crop termination method (P > 0.35), but the interaction between cover type and postemergence glyphosate application rate was significant (P < 0.01). In soybean following a rye cover crop, regardless of termination method, yield was unaffected by glyphosate rate (P = 0.08), whereas in soybean following a vetch cover crop or bare soil, yield increased with glyphosate rate (P < 0.001). Use of a roller-crimper to terminate a cover crop preceding no-till soybean results in similar yields to those obtained by chemically terminating the cover crop, but reduces biomass and seed production of residual weed populations. |
