Effects of Neem Plant Extract (NPE) on soil aggregate stability of coastal plain soil under cultivated management in Abia State, Nigeria

Knowledge about effects of Neem Plant Extracts (NPE) on soil aggregate stability is important for efficient soil conservation practices. This study was, therefore, conducted to evaluate the effects of neem plant extracts on aggregate stability of coastal plain soil in Abia State, Nigeria. The study was carried out in Umudike, Abia State. Undisturbed core and disturbed soil samples were collected randomly from three sampling points with three replications at a depth of (0–15 cm). Results of the study indicated that 50% of NEP under W/D cycle 1 had the highest mean weight diameter (MWD) (4.01 mm). In contrast, control had the lowest MWD (1.97 mm). The application of 100% (MWD) NPE under W/D cycle 5 recorded the lowest (27.56%) dispersion ratio (DR). The highest clay dispersion index (DI) of 68.03% was recorded in the soil treated with 100% Neem Plant Extract under W/D cycle 5. Application of 100% of NPE with no W/D cycle had the highest aggregated silt + clay (18.79%) and clay flocculation index (64.95%). From the results of the study it may be possible to conclude that treatment of neem plant extracts on the soil and subjecting of the soil to different wetting and drying cycles had significant effects on the soil aggregate stability. It is, therefore, recommended that the plant may be used in soil erosion zone to promote ecological restoration.