Long-term cropping systems management influences soil strength and nutrient cycling

Elucidating complex interactions of cover crops and crop residues on soil physicochemical properties is critical to sustaining soil productivity long-term. Our objective was to compare soil strength and chemistry (physiochemical), cover crop residue composition, and soil compaction following 15-years of cropping system implementation under non-tillage. Main effects were cropping sequences of soybean (Glycine max L.), corn (Zea mays L.), and cotton (Gossypium hirsutum L.), grown on a Loring silt loam, and sequences of corn and soybean on a Maury silt loam. Split-block treatments consisted of winter wheat (Triticum aestivwn L.), Austrian winter pea (Piswn sativwn L. sativwn var. w vense) and hairy vetch (Vicia villosa Roth) cover crops, as well as poultry litter, and a fallow control. Soil physicochemical characteristics were evaluated at surface (0-15 cm) and sub-surface (15-30 cm) depths. Overall, soil physicochemical parameters were more affected by long-term cover crops and poultry litter in surface layers, whereas crop rotations impacted soil chemistry at sub-surface layers. High-nitrogen (N) containing cover crops had more desirable composition for soil biota (less recalcitrant), whereas corn had the highest soil carbon (C), N, and C:N ratio, likely owing to the greatest amount of residue being produced under this cropping sequence. Whole profile (0-1.2 m) assessment of soil compaction indicates: continuous cotton > continuous soybean > corn-soybean > continuous corn > corn-cotton, likely owing to greater planting and spraying traffic throughout the cotton production cycle. Study results help identify cropping system management effects on soil physicochemical properties under no-tillage and such data are needed for quantifying soil quality per soil conservation management.