Submitted to: Southern Conservation Tillage Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: 6/25/2007
Publication Date: 6/27/2007
Citation: Kornecki, T.S., Price, A.J., Raper, R.L., Arriaga, F.J., Stoll, Q.M. 2007. Roller type and operating speed effects on rye kill rates, soil moisture and irrigated sweet corn yield in an Alabama no-till system. In: Wright, D.L., Marsis, J.J., Scanbou, K.S., editors. Proceedings of the Southern Conservation Tillage Systems Conference, June 25-27, 2007, Quincy, Florida. p. 188-196. Interpretive Summary: Rye cover crop, which produces a large amount of biomass, has been used in no-till conservation fields in the Southeastern U.S. to protect the soil surface from rainfall and improve soil quality by increasing soil organic matter. There is an increased interest from vegetable producers to utilize cover crops in no-till vegetable and organic systems. Roller/crimpers have been used for flattening and terminating rye. A field experiment was conducted in northern Alabama to evaluate the effects of three different roller/crimpers on terminating a rye cover crop, soil moisture, and sweet corn yield in a no-till system. Three roller/crimper designs were tested at two operating speeds. Termination rates provided by the three roller/crimpers were compared to a smooth drum roller plus Roundup applied at 1 lb/acre. Preliminary results indicate that three weeks after rolling the smooth drum roller with Roundup produced full rye termination. Lower termination rates were reported for all roller/crimpers and most likely were related to rolling rye too soon. Roller type did not affect soil moisture after the first and second week from rolling. Higher sweet corn yield was reported for all roller/crimpers. The lowest yield was found with the smooth drum roller plus Roundup and might be associated with moisture deficiency within the field. Preliminary results suggest that terminating a rye cover crop using roller/crimpers may not be suitable in no-till organic sweet corn production. However, the use of roller/crimpers can still be beneficial in no-till vegetable production where chemicals may be used or where the rolling/crimping operation may be performed at the optimum (early milk/soft dough) stage of cover crop growth.
Technical Abstract: A field experiment was conducted in Cullman, Alabama to evaluate the effects of three different roller/crimpers on terminating a rye (Secale cereale L) cover crop, soil moisture, and sweet corn yield in a no-till system. A straight bar roller, a smooth roller with crimper, and a two-stage roller operated at 2 and 4 MPH were compared to a smooth drum roller with glyphosate (RoundupTM) application, which was used as a control. Based on the results from one (2006) growing season the smooth drum with Roundup application produced the highest rye termination rates of 98%, 100% and 100% compared to roller only treatments (30%, 58% and 68%), one, two and three weeks after treatment application, respectively. Lower mechanical termination was most likely due to rolling/crimping at the anthesis growth stage. Roller type and operating speed did not affect soil moisture after the first and second week from rolling. Despite lower termination by rollers, sweet corn yield was not affected. Unexpectedly higher sweet corn yields were found for all rollers and speeds with the highest yield of 15348 lbs/ac reported for the smooth roller with crimper at 4 MPH compared to the smooth roller drum with Roundup application (11554 lbs/ac). No significant difference in sweet corn yield was found between straight bar roller at 4 MPH, two-stage roller at 2 MPH and smooth roller drum plus Roundup. The lowest sweet corn yield reported for the smooth roller drum plus Roundup might be associated with soil moisture differences related to elevation changes within the study area and unusually dry weather during the growing season.