Location: Soil Dynamics ResearchTitle: Influence of recurrent rolling/crimping on cover crop termination, soil strength and yield in no-till cotton
Submitted to: AgriEngineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2020
Publication Date: 12/17/2020
Citation: Kornecki, T.S. 2020. Influence of recurrent rolling/crimping on cover crop termination, soil strength and yield in no-till cotton. AgriEngineering. 2(4), 631-648. https://doi.org/10.3390/agriengineering2040042.
Interpretive Summary: A scientist at the USDA National Soil Dynamics Lab in Auburn, Alabama investigated effects of multiple rolling/crimping operations utilizing different types of experimental rollers (developed at the NSDL) on cereal rye termination, soil compaction and seed cotton yield in a no-till system. Results from the three growing seasons indicated that one week after rolling, the improved 4-stage and 2-stage rollers, rolled cereal rye 3 times, had termination rates above 90% which were similar to chemical application (glyphosate). Overall, rolling cereal rye 2 or 3 times did not cause soil compaction, and soil strength was dependent on gravimetric soil moisture content having lower soil strength at higher gravimetric soil moisture. Results also have showed that soil strength before rolling were higher compared to lower values after rolling and were related to higher soil moisture. During three growing seasons, soil strength after rolling at 0-15 cm depth did not exceed the 2.0 MPa limit for unrestricted root growth. In addition, seed cotton yield was not affected by rolling 2 or 3 times, indicating that multiple rolling did not cause yield decline.
Technical Abstract: Rollers/crimpers have been used to terminate cover crops typically with supplemental herbicide application to speed-up termination. But due to environmental concerns, there is a need to reduce herbicide use. In the Southern USA, the cash crop is planted 21 days after a rolled cover crop reaches more than 90% termination rate which eliminates competition with the cash crop for water and nutrients. A three-year replicated field experiment was initiated in fall of 2014 to determine the effects of recurring rolling by experimental rollers/crimpers in terminating a cereal rye cover crop in central AL and how multiple rolling affected soil strength. Experimental 2-stage, 4-stage, and spiral rollers were tested to roll rye 1, 2, and 3 times. A smooth roller with mounted spray boom applying glyphosate was also evaluated and untreated rye was the control. Rye was terminated at the milk growth stage and was evaluated 7, 14 and 21 days after rolling. At 7 days after rolling, the highest termination was obtained with rolling three times by the 4-stage (96%), 2-stage (92%), spiral roller (81%); rolling once by the smooth roller with glyphosate (94%) compared to the control at 37%. At 14 days after rolling no differences among rollers were found (91% to 98%); the control was 54%. Similarly, at 21 days after rolling no differences were detected among rollers (99% to 100%); the control was 86%. Results have shown that rolling 2 or 3 times compared with one pass rolling did not cause soil compaction. Soil strength did exceed a critical value of 2 MPa to restrict root penetration at the 15 cm deep root zone and was solely related to decrease in gravimetric soil moisture content (GMC). In addition, over three growing seasons, the seed cotton yield was not affected by rolling treatments producing the average yield of 3601 kg ha-1.