42 years of no-tillage and cover cropping improved soil oxygen availability and resilience

Healthy soil air-water balance is critical for crop growth. Conservation agricultural practices improve soil physical properties to influence soil oxygen availability. We evaluated the impact of 42 years of hairy vetch (HV) cover cropping (CC) and no-tillage (NT) on soil oxygen dynamics during a cotton growing season experiencing multiple intensive rain events in silt loam soil. HV and NT treatments exhibited higher growing season soil oxygen availability (p < 0.05), and experienced 3 to 4 times fewer hours of oxygen limitation (i.e., oxygen concentration <10%) as compared to no cover (NC) and conventional tillage (CT) treatments. After heavy rainfall, NT-HV treatment exhibited the highest soil oxygen availability, followed by NT-NC, CT-HV, and CT-NC treatments (p < 0.05). While CC and/or NT treatments quickly regained soil oxygen status within 24 hours after saturating rain events, CT-NC suffered from sub-optimal soil aeration until the third day post-rainfall. The combination of CC with NT practices enhanced soil oxygen availability and resilience to extreme precipitation events.