Journal of Global Agriculture and Ecology

This study assessed soil macrofaunal and microbial diversity in a date palm plantation at Modibbo Adama University, Yola, Nigeria, within the Sudan-Guinea savannah transition zone. Macrofauna were sampled using 20 m × 20 m plots with 1 m² quadrats at 0–40 cm depth, while microbial isolates were obtained through serial dilution and culture techniques. A total of 29 macrofauna species were documented, with the low-growth site exhibiting the highest species richness (21 taxa) and abundance (529 individuals), followed by high-growth (17 taxa; 377 individuals) and medium-growth (18 taxa; 333 individuals) sites. Diversity indices (Shannon: 2.423-2.716; Simpson: 0.754-0.920) indicated moderate to high species diversity. The community was dominated by ants, termites, earthworms, and oribatid mites. Microbial analysis revealed 20 isolates across 12 families, with Bacillaceae being most prevalent. Gram-staining showed site-specific variations: low-growth sites exhibited mixed Gram-positive and Gram-negative organisms, while medium and high-growth sites were dominated by Gram-positive cocci. Bacterial counts increased from low (7.0-15.0 × 10⁻⁵ cfu/ml) to high (10.0-16.0 × 10⁻⁵ cfu/ml) growth sites, suggesting positive correlation with palm performance. Actinomycete counts ranged from 4.0-22.0 × 10⁻⁵ cfu/ml, while fungal populations showed highest variability in medium-growth sites (6.0-14.0 × 10⁻⁵ cfu/ml). ANOVA revealed significant differences in bacterial and actinomycete counts (p ≤ 0.05) across sites. The co-occurrence of pests (white grubs, rhinoceros beetles, termites) and beneficial organisms (detritivores, predators, decomposer microbes) highlights the plantation's dual ecological nature. These findings demonstrate that date palm soils harbour diverse biological communities serving as sensitive indicators of ecosystem health, with significant implications for sustainable management through enhanced organic inputs, reduced disturbance, and minimised agrochemical reliance.