Integration effects of soil amendments and cover crops on dryland no‐till corn

Abstract

A field study was carried out at the Mississippi Agricultural and Forestry Experiment Station near Pontotoc to evaluate the synergistic impacts of broiler litter (BL) and inorganic fertilizer nitrogen (N) with flue gas desulfurization (FGD) gypsum and lignite in the presence of winter cover crops (WCCs) on dryland no‐till corn (Zea mays L.) in Falkner silt loam soil. The experimental design was a split‐plot randomized complete block design with three replications. The main plots were WCC and winter fallow (WF), and the subplots were fertilization treatments. Fertilization treatments included BL, inorganic fertilizer N, FGD gypsum and lignite with BL, FGD gypsum and lignite with inorganic fertilizer N, and an unfertilized control. BL, FGD gypsum, and lignite were applied at the rates of 13.4, 3.4, and 3.4 Mg ha⁻¹, respectively. Inorganic fertilizer N was applied to corn at 168 kg N ha⁻¹. BL increased soil carbon (C), soil infiltration, and resulted in higher corn grain yield compared to both inorganic fertilizer N and unfertilized control in 2020 and 2022. Averaged across fertilization treatments, WCC improved soil moisture, soil C, and soil infiltration by 16%, 19%, and 25% at the 0‐ to 15‐cm depth, respectively, and increased corn grain yield by 25% as compared to WF in 2022. Cover crops boosted corn grain yield during drier years. The combination of FGD gypsum and lignite with BL increased corn grain yield by 15% in 2020 and 13% in 2022 compared to BL alone. This approach can be considered to promote the sustainability of agroecosystems.