New roller crimper concepts for mechanical termination of cover crops in conservation agriculture

Abstract

Rollers crimpers have been used in conservation agriculture to terminate cover crops; however, excessive vibration generated by the original straight-bar roller design has delayed adoption of this technology in the United States. To avoid excessive vibration, producers generally reduce operating speeds that increase the time needed to perform the field operation. The objectives of this research were to identify roller crimper designs that terminated rye cover crops consistently, resulted in soil moisture conservation after use, and minimized vibrations when operated in the field. Six different roller types were developed and tested at 3.2 and 6.4 km h -1 in Alabama field experiments during the 2006, 2007 and 2008 growing seasons. All roller types were used alone and one also in combination with glyphosate. Rye mortalities were evaluated 1, 2 and 3 weeks after rolling and compared with the check (non-rolled standing rye). Soil volumetric moisture content (VMC) was measured at the day of rolling, and then at 1, 2 and 3 weeks after rolling. Vibration was measured on the rollers' and tractor's frames during operation. Mortality for rolled rye 2 weeks after rolling was at least 98% compared with 96% for the check in 2006, 93% for rolling compared with 75% for the check in 2007, and 94% for rolling compared with 60% for the check in 2008 (P < 0.10). There were no consistent differences in rye mortality across roller types (without glyphosate) and speeds. VMC for soil in non-rolled rye plots was consistently lower than in rolled rye plots, averaging 3% compared with 7% 2 weeks after rolling in 2006, and 4% compared with 8% in 2008. During 2007, VMC was affected by severe drought conditions, and differences between roller treatments were detected but minor. The straight-bar roller generated the highest vibration on the tractor's frame at 6.4 km h -1 (0.71 m s -2 , RMS), which exceeded International Standards (International Standard Office (ISO)). At 6.4 km h -1 , new roller designs generated significantly lower acceleration levels from 0.12 to 0.32 m s -2 on the tractor's frame and were below detrimental effects on health 'health limits' classified by ISO. Overall, 2 weeks after rolling, all roller designs effectively terminated rye above 90%, which is the recommended termination level of rye to plant a cash crop into residue mat, while protecting soil surface from water loss. New roller designs generate less vibration than the original design and can be used safely at higher operating speeds.

Impacts of Organic Zero Tillage Systems on Crops, Weeds, and Soil Quality

“…The two researchers concluded that small-grain cover crops could be killed effectively if rolling-crimping was delayed until advanced growth stages (Zadoks growth stage, ZGS 85; [30]). Recent roller-crimper designs have improved efficacy of killing cover crops and enhanced operator comfort when used in the field [31][32][33]. Current models can kill over 90% of a rye cover crop when terminated as early as 50% anthesis or ZGS 65 in some environments [34].…”

Establishing the relationship of soil nitrogen immobilization to cereal rye residues in a mulched system

“…A roller-crimper is a ground-driven implement that physically terminates near-mature cover crops before no-till cash crop planting, leaving a surface mulch of cover crop shoot residues as well as intact belowground root residues (Ashford and Reeves 2003;Reberg-Horton et al 2012;Wells et al 2013). Used for many years in Brazil (Derpsch et al 1991), roller-crimping cover crops in annual row-crop systems increased in popularity in the US following improvements in roller-crimper design (Kornecki et al 2009). …”

Integrating a complex rotation with no-till improves weed management in organic farming. A review

“…Scientists are exploring cultural tactics to reduce intensity of tillage (Peigne et al 2007;Maader and Berner 2012). Methods such as strip tillage (Brainard et al 2013) or a crimper-roller that mechanically kills cover crops (Kornecki et al 2009) have been developed. These methods have led to a concept of rotational tillage, where reduced or no-till sequences are integrated within a longer tillage-based rotation (Legere et al 2013).…”