Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2015
Publication Date: 12/7/2015
Publication URL: http://handle.nal.usda.gov/10113/5196590
Citation: Kornecki, T.S. 2015. Rye termination by different rollers/crimpers developed for no-till small-scale farms. Applied Engineering in Agriculture. 31(6):849-856. doi:10.13031/aea.30.10395.
Interpretive Summary: Cover crops are an essential component of no-till agriculture and they improve soil quality, provide better weed control and conserve soil moisture. A common method to manage cover crops is using rolling/crimping technology. Small scale producers need rollers compatible with small tractors already used on farms. To address these needs, a 3-year field experiment was initiated in fall of 2011 in central Alabama to determine the effectiveness of three rollers/crimpers (one commercially available roller and two experimental prototypes) designed for walk-behind tractors. Rollers were operated at two speeds and from one to three rolling passes during the springs of 2012, 2013, and 2014. In three years at two weeks after rolling, rolling/crimping three times generated increased termination rates compared to rolling/crimping once or twice. Overall, across three growing seasons, the rye termination rates generated by the experimental powered roller/crimper and the two stage roller/crimper were consistently higher compared to a commercially available chevron type, curved roller/crimper. In 2012, soil water conservation was improved by rolled residue within one week after rolling, whereas in 2013, soil moisture for rolled rye was higher compared to standing rye one, two, and three weeks after rolling due to higher rye biomass that created better soil coverage. In 2014, two weeks after rolling, rolling once vs. three times or rolling twice vs. three times improved soil water content. One and two weeks after rolling, rolled down rye residue better conserved soil water compared to standing rye.
Technical Abstract: The expansion of fresh food production by local small vegetable farms must be associated with sustainable practices that include no-till systems with proper cover crop management. When cover crops are terminated at an appropriate growth stage, the unincorporated residue protects the soil from erosion, runoff, soil compaction, and weed pressure, and conserves soil water. In the Southern United States, the recommended time to plant cash crops into residue cover is typically three weeks after terminating the cover crop, when the termination rate exceeds 90% and competition for resources is minimized between cover and cash crops. One method to properly manage and terminate cover crops is to use rolling/crimping technology. Small scale producers need rollers/crimpers compatible with small tractors already used on farms. To address this need, a field experiment was conducted during the springs of 2012, 2013, and 2014 to determine the effectiveness of one commercially available and two experimental roller/crimpers designed for walk-behind tractors. Each roller was operated at 1.6 km h-1 and 3.2 km h-1 and rye was rolled once, twice, and three times each season. In 2012, at one, two, and three weeks after rolling, the experimental powered roller generated rye termination rates of 91.0%, 92.9%, and 99.9%, while the two-stage roller generated 87.7%, 94.1% and 99.8%, respectively, compared to a commercial curved chevron type roller which generated termination rates of 74.7%, 87.6%, and 98.6%. One week after rolling, soil volumetric moisture content (VMC) for all rolled rye residue was higher (8.5%), compared to standing rye (5.4%) indicating better water conservation due to rolling. In 2013, rye termination rates by all rollers were lower compared to 2012 due to higher rye biomass in 2013 (9604 kg ha-1 vs. 8228 kg ha-1), higher moisture content (14% vs. 10%) and in 2013 rye was terminated at an earlier rye growth stage (early milk vs. soft dough). The powered roller generated rye termination rates of 79.9%, 85.9%, and 89.3% which exceeded the 75.5%, 83.1%, and 86.6% obtained by the two-stage roller, at one, two, and three weeks after rolling. During the same period, the commercial roller generated termination rates of 54.7%, 69.6%, and 77.1% which were lower than for the experimental rollers. One, two and three weeks after rolling, VMC for standing rye was 6.7%, 13%, and 7.8%, compared to much higher VMC for all rolling treatments of 11.6%, 17%, and 13.7%, respectively, indicating that rolled residue conserved soil moisture by superior soil coverage, due to a mulch effect. In 2014, the powered roller generated rye termination rates of 76.3%, 89.9%, and 100%; the two-stage roller generated 73.0%, 89.5% and 100%, one, two, and three weeks after rolling, respectively, compared to the commercial roller which generated termination rates of 52.0%, 77.7%, and 99.9%. In three growing seasons, at two weeks after rolling, rolling/crimping three times generated increased termination rates compared to rolling/crimping once or twice. Increasing operating speed generated slightly higher termination rates one week after rolling in 2012 (86.2% vs. 82.8%) and in 2014 (69.1% vs. 65.1%), whereas in 2013 higher termination rates were higher one week (72.4% vs. 67.7%), two weeks (81.3% vs. 77.8%) and three weeks after rolling (86.3% vs. 82.4%). Overall, the experimental rollers generated higher rye termination rates compared with the commercial roller, and these higher rates are most likely related to greater dynamic crimping action of the crimping bars in the experimental rollers, where crimping energy is released from springs, rather than relying on the limited weight of the roller as with the commercial roller.