Journal of Agricultural Science and Practice

The widespread use of agrochemicals in semi-arid agricultural systems raises concerns about their persistence, mobility, and effects on non-target organisms and ecosystem health. This study assessed the agrochemical footprint in soil and foliage of date palm (Phoenix dactylifera L.) and its effects on macrofaunal and microbial diversity under agrisilvicultural practice in Damaturu, Yobe State, Nigeria. The plantation was stratified into high-, medium-, and low-growth sites based on observed growth variability. Soil samples were collected at 0–60 and 61–90 cm depths for physicochemical analysis, pesticide residue determination using Gas Chromatography-Mass Spectrometry (GC-MS), and microbial enumeration. Foliar samples were also analysed for pesticide residues, while macro-invertebrates were sampled using 20 m × 20 m plots and 1 m × 1 m quadrats. Results showed that soils were sandy loam with slightly acidic pH (6.06–6.40), low total nitrogen (0.12–0.15%), and low water-holding capacity (10.93–11.28%). The high-growth site recorded superior nutrient status, including available phosphorus (11.23 mg kg⁻¹), calcium (5.47 cmol kg⁻¹), and magnesium (2.42 cmol kg⁻¹). Pesticide residues detected included chlorpyrifos (0.17 µg/kg), dichlorvos (0.44 µg/kg), 2,4-D (0.42 µg/kg), alachlor (0.33 µg/kg), cypermethrin (0.34 µg/kg), butachlor (0.16 µg/kg), and atrazine (0.08 mg/kg). Residues were also detected at 61–90 cm, indicating downward mobility through infiltration. Macro-invertebrate abundance was highest at the high-growth site (365 individuals), representing 14 taxa, while the medium-growth site recorded the highest Shannon-Wiener diversity (H′=1.823) and evenness (J=0.4763). Microbial populations varied significantly (p≤0.05), with the medium site recording the highest bacterial (54.8 cfu/ml) and fungal (50.6 cfu/ml) populations, whereas the low site had elevated actinomycetes (140 cfu/ml) and reduced bacterial counts (33.0 cfu/ml). The study concludes that agrochemical contamination influences soil quality and biological community dynamics, particularly at the low-growth site. Integrated pest management, routine monitoring, organic matter amendment, conservation practices, and strengthened regulatory enforcement are recommended for sustainable date palm production in semi-arid environments.