Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 10/13/2013
Publication Date: 10/13/2013
Citation: Kornecki, T.S., Price, A.J., Balkcom, K.S. 2013. Effects of terminating cover crops with rolling/crimping and herbicides on cotton population and yield in an Alabama no-till system. In: Proceedings of the Synergy & Technical Development International Conference, October 13-19, 2013, Godollo, Hungary. 6 pages.
Interpretive Summary: In conservation systems cover crops are used to improve soil quality, weed control and save moisture. A common method to speed-up cover crop termination is to apply synthetic herbicides in addition to mechanical rolling. This study was done in central Alabama looking at effects of rolling/crimping and different herbicides rates on rye and clover termination, and cotton growth. Termination was faster with continuous or reduced applications of glyphosate compared to the roller alone, but not with organic herbicides. Rolling and herbicides did not influence cotton population. Cotton yield following rye was higher than using clover. This was probably due to nitrogen released by clover that promoted vegetative growth over reproductive growth. In general, rolling and herbicides did not have an impact on cotton growth.
Technical Abstract: In fall of 2008, a field experiment was initiated in central Alabama to study the effects of rolling/crimping and different herbicides with different application rates on cover crops termination rates, cotton population and yield. Results from 2009 and 2010 growing seasons are presented. A roller/crimper only and with supplemental use of two organic herbicides (Weed-Zap and vinegar 20% acidity) and glyphosate were applied as a continuous spray, every second crimp and every third crimp controlled by a high speed solenoid valve nozzle system to terminate cereal rye and crimson clover. In 2009, three weeks after rolling, termination rates due to rolling/crimping and herbicide treatments for cereal rye were between 96-100%, whereas for crimson clover were lower (75% –82%) because of moisture excess. Three weeks after rolling, in 2010, termination rates for cereal rye were 96% to100%, and between 93% to 100% for crimson clover. In 2009, rolling treatments and cover crop type had no effect on cotton population which averaged 45,830 plants/ha. Contrary, in 2010 cotton population due to rye was lower: 27291 plants/ha compared to 47411 plants/ha due to clover. In 2009, significantly higher average seed cotton yield was 3494 kg/ha for cereal rye compared to 2853 kg/ha for crimson clover. Lower cotton yield with crimson clover might be associated with a higher vegetative plant growth due to Nitrogen release from crimson clover residue. In 2010 cotton yield was affected by very wet summer. Average yield for rye was 1793 kg/ha, whereas for crimson clover the seed cotton yield was 1638 kg/ha. Overall, rolling and herbicides did not affect cotton population and yield. In contrast, cotton population and yield were affected by different weather conditions during growing seasons of 2009 and 2010.