Submitted to: Annual Southern Conservation Tillage Conference for Sustainable Agriculture
Publication Type: Proceedings
Publication Acceptance Date: 7/29/2008
Publication Date: 7/29/2008
Citation: Kornecki, T.S., Price, A.J., Raper, R.L., Arriaga, F.J., Schwab, E.B. 2008. Effects of rolling/crimping of cover crops on their termination, soil strength and moisture. In: Endale, D.M., editors. Proceeding of the 30th Southern Conservation Agricultural Systems Conference and 8th Annual Georgia Conservation Production Systems Training Conference, July 29-31, 2008, Tifton, GA. p.100-104. Interpretive Summary: Mechanical termination of cover crops using a roller needs to be done at least three weeks before planting cash crops into residue. To speed up termination, growers use herbicides as a supplement to rolling. However, in organic vegetable production, common herbicides cannot be used and multiple rolling operations may be needed. But multiple rolling might cause soil compaction which could limit water infiltration and plant root growth. This field study evaluated multiple rolling/crimping operations on termination rates of two cover crops: rye and mixture (rye, crimson clover and hairy vetch). Multiple rolling did not increase soil compaction, but did increase rye termination and preserved soil moisture compared with non-rolled cover crops. Multiple rolling of cover crop mixtures did not speed-up termination even after three rolling/crimping applications.
Technical Abstract: Termination of cover crops in conservation systems has been accomplished by rolling down and crimping covers using rollers/crimpers. Three weeks after rolling is typically required to plant a cash crop into residue covers. A common method to speed-up a cover crop termination is application of herbicides. Herbicides cannot be used in organic production, thus multiple rolling may be necessary. To determine the effect of multiple rolling operations on soil strength, termination rate and soil water content, two rollers, straight-bar roller and two-stage roller, were used in a replicated field experiment in the spring of 2007. Cover crop termination rates were evaluated one, two, and three weeks after rolling. The objectives of this study were to determine the effectiveness of two different roller designs in terminating a single cover crop (rye) and mixture (rye, clover, hairy vetch) in multiple rolling operations, and the effect of multiple rolling on gravimetric soil water content and soil strength (Cone Index, CI). Both roller types effectively terminated rye (> 90%) three weeks after rolling, which was above the recommended rye termination rates to plant a cash crop. Rolling two or three times did not cause soil compaction, and rolled residue kept soil strength (Cone Index) significantly lower compared to standing cover crops. Gravimetric soil water content after multiple rolling was significantly higher compared with standing rye and mixture covers. In the mixture, hairy vetch, even after three rolling/crimping applications was actively growing two weeks after rolling. Multiple rolling can be beneficial for faster mechanical termination of single cover crops such as rye but not for mixtures.