Impact of no-till, crop rotation, cover crop, and drainage on soil physical and hydraulic properties

Conservation agriculture and associated soil health practices potentially enhance soil resilience by improving the soil's physical, chemical, and biological properties and processes. This study assessed the impact of tillage (conventional tillage [CT] and no-till [NT]); crop rotation: 2-year corn (Zea mays L.)-soybean (Glycine max L.), 3-year corn-soybean-oat (Avena sativa L.), and 4-year corn-soybean-oat-wheat (Triticum aestivum L.)]; cover crops (cover crop [CC] and no cover crop [NC]); and drainage (tile drainage [TD] and without drainage [ND]) on soil organic matter (SOM), bulk density, wet aggregate stability (WAS), and field-saturated hydraulic conductivity (Kfs). Soil samples were collected over 2 years apart from five depths (0-10, 10-20, 20-30, 30-60, and 60-90 cm) and analyzed for SOM, bulk density, and WAS. In-situ infiltration tests were conducted in each plot to determine field-saturated hydraulic conductivity. This study showed that NT practice significantly increased SOM by 5.4%, WAS by 7.7%, and bulk density by 6.7% within 0-10 cm soil profile but decreased Kfs by 47.6% compared to CT through increased bulk density in the topsoil. NT increased SOM for every soil depth and, similarly, increased WAS for every depth but only statistically significant increases occurred at 0-10 cm and 60-90 cm. Further, higher crop diversity decreased bulk density and increased WAS. Nine years of CC and six years of tile drainage practices had no significant effect on SOM, bulk density, WAS, and Kfs. Long-term no-till (NT) has a significant impact on soil physical and hydraulic properties.NT increased soil bulk density, soil organic matter (SOM), and wet aggregate stability (WAS) by 6.7%, 5.4%, and 7.7%, respectively, for 0- to 10-cm depth but decreased Kfs by 47.6% within profile than conventional tillage (CT).Compaction decreased at 0-10 cm in CT but increased within the 10-60 cm soil profile.NT with more diverse rotation and cover crop (CC) practices showed limited or no positive impact on Kfs for silt clay loam.CC and tile drainage(TD) had minimal impact on SOM, bulk density, WAS, and Kfs under silt clay loam in southeastern South Dakota.