Recurring rolling/crimping effects on termination effectiveness for iron clay pea and pearl millet warm season cover crops

Authors: Kornecki, Ted; Kichler, Corey

Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2023
Publication Date: 10/6/2023
Citation: Kornecki, T.S., Kichler, C.M. 2023. Recurring rolling/crimping effects on termination effectiveness for iron clay pea and pearl millet warm season cover crops. Agriculture. 13(10):1949. https://doi.org/10.3390/agriculture13101949.
DOI: https://doi.org/10.3390/agriculture13101949

Interpretive Summary: Summer cover crops utilization is essential for continuous soil protection especially in the southern United States where intense storms are likely to occur in hot and humid summer months. Two cover crops iron clay peas and pearl millet were selected to determine termination rates effectiveness in single, double, and triple rolling/crimping over the same cover crop area. A field experiment was conducted at the National Soil Dynamics Laboratory in Auburn, Alabama, USA during summers of 2015, 2016 and 2017 to determine the effectiveness of an experimental 2-stage roller/crimper in mechanical terminating of summer cover crops. Iron clay pea was planted on a sandy loam and pearl millet was planted on a clay soil. Overall, termination rates for both cover crops were higher for rolling three times, compared to rolling once or twice. However, cover crops termination was inhibited due to rainfall that had fallen on the experimental area during the three-week evaluation period. Rolling for both cover crops provided higher soil-water conservation compared with the non-rolled control due to mulching effect from soil coverage. Recurrent rolling on the same area showed only minimal increases in soil hardness, which was dependent on soil moisture content.

Technical Abstract: Summer cover crops utilization by no-till vegetable farms is essential for continuous soil protection, especially in the southern United States where intense storms are likely to occur in hot and humid summer months. A field experiment was conducted at the National Soil Dynamics Laboratory in Auburn, Alabama, USA between summers of 2015-2017 to determine the effectiveness of an experimental roller/crimper in mechanical terminating of summer cover crops. Iron clay peas (Vigna unguiculata, L.) planted on a sandy loam and pearl millet (Penninsetum glaucum, L.) planted on a clay soil were selected to determine termination rate effectiveness in single, double, and triple rolling/crimping over the same area. Overall, termination rates for both cover crops were higher for rolling three times (71%), compared to rolling once (55%) or twice (63%). However, cover crops termination was inhibited due to rainfalls on the experimental area during the three-week evaluation period. In 2016 drought conditions and high temperatures (32.6 oC) caused biomass reduction, especially for pearl millet, of over 31% to 39% compared to 2017 and 2015. Rolling provided higher soil-water conservation compared with the non-rolled control due to mulching effect. Recurrent rolling did not cause soil compaction above the 2.0 MPa level that inhibit root growth but changes in soil strength were dependent on soil moisture content.