Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/30/2004
Publication Date: 8/30/2004
Citation: Kornecki, T.S., Price, A.J., Raper, R.L., Arriaga, F.J., Balkcom, K.S. 2004. Effectiveness of different mechanical roller designs for terminating cover crops. In: Zhieai, W., Huawen, G., editors. Conservation Tillage & Sustainable Farming China Agricultural Science and Technology Press. 2004 CIGR International Conference, October 11-14, 2004, Beijing China. p. 218-229. Interpretive Summary: Cover crops have been identified as an essential part of conservation tillage systems. However to obtain maximum benefits, cover crops must be managed appropriately. Rolling and crimping of cover crops provide a sufficient soil cover which prevents weed emergence and increase soil available moisture. Also, rolling of cover crops in the direction of planting provides minimum interference for cash crops. Rollers (round steel drums with attached blunt blades) have been successfully used to roll and crimp cover crops in South America without using herbicides. However, high vibrations at typical U.S. field operating speeds limit the number of producers who are willing to adopt this technology. This study identifies vibration problems for 3-single section different roller designs, and also compares vibration levels and killing rates for 2-tripple sections designs (commercial widths). Data have shown that after three weeks from rolling single and triple-section rollers effectively terminated cover crop (above 94%) without the need to use herbicides. At higher operating speeds the smooth roller with a crimping arm transferred significantly lower vibration to the tractor's frame in comparison with straight and elliptical blades. This research is intended to develop rollers which generate significant less vibration, and to further improve termination rate of cover crops at speeds matching or exceeding typical speeds used in herbicide applications.
Technical Abstract: Rollers may provide a viable alternative to herbicides for terminating cover crops, however, excessive vibration levels generated by rollers do not allow adoption of this technology. To improve the roller's performance, two field experiments were conducted with different roller designs to terminate a cover crop (rye). In experiment 1, three-single sections of rollers: straight bars, elliptical bars, and a smooth roller with an oscillating crimping bar- were tested at speeds 1.6, 4.8, and 8 km/h. In experiment 2, a triple-section roller (commercial width) with straight bars and a smooth roller with an oscillating crimping bar- were tested at speeds 3.2, and 6.4 km/h. For single-section rollers, the highest kill rate of rye after 3 weeks from rolling was produced by the smooth roller with crimping bar (93%). Rollers operated at higher speed (8 km/h) produced a significantly higher kill rate of the cover crop compared to low speed (1.6 km/h). Minimum vibration levels measured on tractor's frame were generated by smooth roller with oscillating crimping arm. For Experiment 2, three weeks after rolling there was no significant difference in killing rates between roller types with cumulative kill rates of 95%; however, smooth roller with crimping bar transferred significantly lower vibration levels to the tractor's frame at both speeds.