Impact of no-till, cover crop, and tile drainage system on soil moisture dynamics within 0–120 cm soil profile

Rainfed crop productivity in the Northern Great Plains is often limited by soil moisture variability. Agricultural conservation practices can reduce this variability by enhancing soil hydro-physical properties. This study evaluated the impact of three practices: tillage [conventional tillage (CT) and no-till (NT)], cover crops [cover crop (CC) and no cover crop (NC)], and drainage [tile drainage (TD) and no drainage (ND)] on volumetric water content (VWC) for two growing seasons in a rainfed 3-year crop rotation system (corn–soybean–oat) with silty clay loam soils. Twenty-four Sentek Drill&Drop Bluetooth Probes were installed to monitor hourly (VWC) at 12 soil depths (0–120 cm) from April 2021 to October 2022. Further, the Soil-Plant-Air-Water (SPAW) model was used to simulate the agro-hydrological components for corn (2021) and soybean (2022) production phases. Average VWC was significantly higher (3.8%) in NT than CT across the profile, primarily increased infiltration (+10%) and reduced runoff (-56%) during average weather years. VWC was significantly higher in NT compared to CT at 5 cm, 15 cm, and 115 cm depths—by 6.4%, 11%, and 4%, respectively. During the 2022 drought, soybeans yielded 44% higher and 47% higher water productivity in NT than CT. In contrast, CC and TD had minimal overall impacts on seasonal VWC. CC enhanced VWC under adequate precipitation in 2021 but depleted reserves during the 2022 drought. The study concludes that long-term no-till acts as a vital moisture buffer, overcoming physical constraints to enhance climate resilience and yield stability in rainfed silty clay loam soils.