Tracy Okeoghene OBARO

This study investigated the residual effects of selected organic amendments on the physical, chemical, and microbial properties of soils previously cultivated with bell pepper (Capsicum annuum L.).The experiment was laid out in randomised block design (RCBD) with twelve different treatment representing sole treatment(T1(control) T2 (Poultry manure) T3 (Mychorriza) T4( Black soldier flyfrass)T5 (Digestate) and the rest as combined treatments. This research compared data from soil samples collected from the previous cultivation season in 2024 with soil samples of the post harvest period (2025) to evaluate changes in soil quality, the continuous and sustained effects of amendments over time. The results from the analysis shows that There was a decrease in pH from 2024 to 2025, from(6.47to6.00) in T2(PM), while organic matter and organic carbon showed a general increase from (5.30 to 34.60 g/kg) and (3.10 to 20.10 g/kg) in T12(DIG+PM) respectively. In comparing 2024 and 2025, bacterial counts increased across all treatments, while fungal counts declined. Results revealed that while some nutrient parameters declined compared to the initial season (2024 cropping season), soils that previously received combined organic treatments maintained significantly improved fertility indices relative to the control. These findings demonstrated that the amendments not only improved soil fertility during the first year but also had lasting residual benefits that continued enhancing the soil even without re-application. Also this study recognizes T12(DIG +PM) as the best most sustainable amendments because it effectively balanced nutrient supply, organic matter input, and microbial stimulation leading to enhanced soil fertility and lasting residual effects. Keywords: Poultry manure, Digestate.