Cover-crop effects on near-surface soil physical properties, infiltration, and nematodes over time in the Lower Mississippi River Valley

Human population growth and climate change are stressors that continue to put pressure on current agricultural production systems. Cover crops (CC) as a means to improve soil health remain widely underused, particularly in the Lower Mississippi River Valley. The objective of this study was to evaluate the effects of CC on the change over time in near-surface bulk density, aggregate stability, total infiltration and steady-state infiltration rate, and nematode populations in eastern Arkansas. Averaged across depth, bulk density did not change over time under a no cover crop (NCC) treatment, but increased approximately 0.03 g cm⁻³ over time under CC. Averaged across CC treatment and aggregate size-class, water-stable aggregate (WSA) concentration differed by depth, with an increase over time of 0.012 g g⁻¹ within the 0- to 5-cm, but did not change over time in the 5- to 10-cm soil depth. Total water-stable aggregate (TWSA) concentrations differed between CC treatments over time, increasing more under CC (0.054 g g⁻¹) and no change under NCC. Total WSA concentration increased over time in the 0- to 5-cm (0.061 g g⁻¹) depth, but did not change over time in the 5- to 10-cm depth. Between Spring 2019 and 2020, reniform (Rotylenchulus spp.) and spiral (Helicotylenchus spp.) nematode abundances differed between CC treatments, with an increase in population count under CC (872 and 116, respectively), while populations did not change over time under NCC. Results of this study emphasized the importance of the temporal nature of soil health as affected by CC and their potential to improve soil health in Arkansas.