Location: Soil Dynamics ResearchTitle: Effect of different rolling/crimping directions and row cleaners for cereal rye cover crop on cotton growth in a conservation system
Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2018
Publication Date: N/A
Interpretive Summary: This three year field research at central and northern Alabama evaluated the effects on different rolling patterns for cereal rye cover crop [0 (parallel), 15, 180, and 195 degrees] with respect to cotton planting directions using a roller/crimper and different row cleaners (DAWNTM or prototype residue pusher with or without coulter) on no-till cotton. Generally, rolling directions did not affect seed cotton yield. In contrast, the yield was affected by row cleaner treatments. Not using a row cleaner resulted in the lowest cotton yield. Both rolling directions and row cleaners affected cotton population, seed cotton emergence rate, residue accumulation on planter, and time to remove residue from planting units. Overall, with large amounts of cover crop residue, rolling down cover crop is important in obtaining higher cotton population. Utilizing row cleaners, with a coulter, was essential in better cotton establishment. The rotation of row cleaners while the planter was moving forward caused tight residue wrapping on row cleaner axles, requiring the longest removal time. The custom V-shaped residue pusher performed satisfactorily, to improve planter performance.
Technical Abstract: Cover crops have been recognized as a vital part of conservation agriculture and must produce optimum biomass to be effective. Because of the large amount of residue produced by cover crops, they need to be managed appropriately to avoid planting problems. Roller/crimpers have been used to roll down cover crops by flattening them and creating a thick residue layer over the soil surface. Preferred rolling direction is parallel to cash crop planting, but producers have been inquiring if other rolling directions are also effective. To answer this question, field experiments were conducted at two locations in central Alabama (EVS) and northern Alabama (TVS) evaluating rye rolling directions: non-rolled (standing) rye, parallel, 180 degrees (opposite), 15 degrees offset from parallel, and 195 degrees (15 degrees offset from 180 degrees) with respect to cotton planting direction using a roller/crimper. To plant cotton, a no-till planter with different row cleaners: no-row cleaner, DAWNTM, and a residue pusher with and without coulter were used to determine effects on rolling direction and row cleaners on cotton stand, emergence rate, and yield under different soil and weather conditions. A split (strip) plot design with four replications was utilized in this study. Cereal rye was chosen as the cover crop due to its popularity in Alabama because of large biomass production. Experiments were performed during the 2009, 2010, and 2011 growing and harvest seasons. Rye was terminated at the early milk growth stage with a roller/crimper with supplemental application of Roundup (glyphosate). Results have shown that significant differences existed among growing seasons (years) and locations with respect to cover crop production, cotton population (stand), emergence rate index (ERI), seed cotton yield, amounts of residue accumulated on planters and time to clean rye residue from planting units. Across three years, rye biomass was greater at the EVS location (6345 kg ha-1) compared to lower biomass (3212 kg ha-1) at the TVS location and was related to rainfall amounts during cover crop development. In contrast, cotton population, emergence rate index, and seed cotton yield were higher at the TVS (stand = 109,881 plants ha-1; ERI = 7.5; yield = 3122 kg ha-1) compared to EVS (stand = 101,313 plants ha-1; ERI = 6.6; yield = 2585 kg ha-1). Because of greater biomass production at EVS, residue accumulation on the planter (6 kg ha-1) and time to remove accumulated residue (0.36 h ha-1) was also greater compared to TVS location with lower residue accumulated (0.7 kg ha-1) and 1/3 of the time to remove residue (0.12 h ha-1). Data indicate that across all growing seasons and locations, rolling direction, and row cleaner treatments did affect cotton population, emergence rate index, residue accumulation on planter, and time to remove residue from planting units; treatments also affected these variables in the specific growing season and the location. In contrast, rolling direction treatments did not affect seed cotton yield, but row cleaner treatments had an overall effect on seed cotton yield.