Conservation management effects on soil and agronomic properties in a furrow-irrigated corn system in east-central Arkansas

Cover crops can improve soil physical properties and help to sustain agricultural crop yields. A 6-year study conducted from 2017 to 2022 examined the effects of conservation soil management practices in a furrow-irrigated continuous corn (Zea mays L.) system on a silt-loam soil (Typic Albaqualf) in the Lower Mississippi River Delta region of eastern Arkansas. This study compared the effects of conventional tillage (CT), no-tillage (NT), and no-tillage with cover crops (CC) in selected soil physical and chemical properties (i.e., soil bulk density (D_b), porosity (ƒ_t), field capacity (Θ_FC), Permanent wilting point (Θ_PWP), Plant available water (Θ_PAW), Total nitrogen (TN), and Soil organic matter (SOM), grain yield, and water-use efficiency. This study provides novel insights into the medium-term effects of combining conservation practices like CC and NT on crop yield, irrigation decisions, and soil dynamics in furrow-irrigated systems, a largely underexplored area in Arkansas. After 6 years of consistent management, soil properties in the upper 15 cm, including D_b, ƒ_t, Θ_FC, Θ_PWP, Θ_PAW, TN, and SOM, were unaffected by treatments. The 6 years of consistent management practices were insufficient to induce substantial variations in the selected soil physical properties across the three soil managements. Averaged across years, corn yield did not differ between the CT and NT. The CC system reduced corn yield by 1.41 Mg ha⁻¹ year⁻¹ over the 6-year experiment compared to the NT system alone. Overall, this medium-term study demonstrated that corn producers can safely convert from a CT system to a NT system without a yield penalty.