Crop species in no-tillage summer crop rotations affect soil quality and yield in an Alfisol

Incorporation of cover crops in no-tillage (NT) cropping systems can be constrained by economic and climatic barriers. In such condition, region-specific crop rotations can diversify and increase biomass input and improve soil quality. We aimed to evaluate the 15-yr impact of six cropping systems including corn-corn (Zea mays L.) (CC), soybean-soybean [Glycine max (L.) Merr.] (SS), cotton-cotton (Gossypium hirsutum L.) (TT), corn-soybean (CS), cotton-corn (TC), and soybean-cotton (ST) on soil hydro-physical properties and yield on a no-till system. Study was conducted on a Loring silt loam (fine-silty, mixed, active, thermic Oxyaquic Fragiudalfs) at Milan, TN. Incorporation of cotton in the cropping system increased near-surface penetration resistance by 17%. Field soil moisture during dry periods (θvd) was 18% greater in corn-soybean and continuous corn than other cropping systems. Including corn in cropping system also increased the wet aggregates stability (WAS) in the top 15cm and geometric mean diameter (GMD) in the top 30cm. Among all treatments, corn-soybean resulted in the greatest field-saturated hydraulic conductivity (Kfs=25.2cmday−1), cumulative infiltration after 200min (I=114mm), and plant-available water content (PAWC=0.20cm3cm−3). However, mean values were only different (p<0.05) between corn-soybean and cotton cropping systems. In accordance with the soil properties, the corn-soybean produced the greatest corn (10Mgha−1) and soybean (3.1Mgha−1) among all treatments. The cotton-corn rotation, despite showing a non-significant advantage in most soil physical properties over other cotton cropping systems, except for greater macroaggregation, produced 13% and 37% greater cotton yield than continuous cotton and soybean-cotton, respectively. Regression analysis indicated the large water retention capacity (θvd and PAWC) as the common characteristics of large corn and soybean yielding cropping systems. Overall, the inclusion of corn in double crop rotations with soybean and cotton improved soil hydro-physical quality and/or yield. Continuous corn improved soil structure and did not negatively affect the corn yield.