Evaluation of Influence of Regular use of Agrochemicals on Physicochemical Properties of Floodplain Soils in Awka North
Authors: Ilouno, E. E., Okafor, M. J.
Journal: American Journal of Applied Sciences and Engineering (AJASE), ISSN 2766-7596
Citation: AJASE 6(4): 1-11, 2025-12-20.
DOI: 10.5281/zenodo.17965037
PDF: Download full-text PDF
Type: Original Research
Abstract
This study evaluated how the regular use of agrochemicals influences the physicochemical properties and selected heavy-metal concentrations of floodplain soils in Awka North, focusing on rice fields and their adjacent fallow lands in Amanuke and Mgbakwu. Soil samples were analyzed for particle size distribution, pH, organic carbon, total nitrogen, exchangeable bases, aluminium, hydrogen, available phosphorus, and trace metals (Cu, Cd, Pb). The results showed that although soil texture remained sandy loam across locations, continuous rice cultivation produced noticeable shifts in soil chemistry. In Amanuke, rice fields contained higher organic carbon, nitrogen, available phosphorus, and acidity-related components (Al³⁺ and H⁺), indicating the cumulative influence of fertilizer inputs and organic residues. Mgbakwu soils showed fewer differences between cultivated and fallow sites, suggesting a lower intensity of input use or stronger natural soil buffering. Heavy metal concentrations were generally low, but cadmium was significantly higher in Amanuke rice soils, pointing to possible accumulation from phosphate fertilizers. Lead also showed a small but significant increase in Mgbakwu rice fields. Although these concentrations remain within international safety limits, their patterns suggest early signs of trace-metal enrichment. Correlation analyses revealed strong relationships among acidity, organic matter, nutrient availability, and metal behavior, especially in Amanuke, showing how agrochemical use is gradually reshaping soil chemical interactions. Keywords Eco-Friendly Paving Blocks; Indigenous Materials; Sustainable Construction Materials Citation
Keywords
Eco-Friendly Paving Blocks, Indigenous Materials, Sustainable Construction Materials Citation Ilouno, E. E. & Okafor
Full Text
This study evaluated how the regular use of agrochemicals influences the physicochemical properties and selected heavy-metal concentrations of floodplain soils in Awka North, focusing on rice fields and their adjacent fallow lands in Amanuke and Mgbakwu. Soil samples were analyzed for particle size distribution, pH, organic carbon, total nitrogen, exchangeable bases, aluminium, hydrogen, available phosphorus, and trace metals (Cu, Cd, Pb). The results showed that although soil texture remained sandy loam across locations, continuous rice cultivation produced noticeable shifts in soil chemistry. In Amanuke, rice fields contained higher organic carbon, nitrogen, available phosphorus, and acidity-related components (Al³⁺ and H⁺), indicating the cumulative influence of fertilizer inputs and organic residues. Mgbakwu soils showed fewer differences between cultivated and fallow sites, suggesting a lower intensity of input use or stronger natural soil buffering. Heavy metal concentrations were generally low, but cadmium was significantly higher in Amanuke rice soils, pointing to possible accumulation from phosphate fertilizers. Lead also showed a small but significant increase in Mgbakwu rice fields. Although these concentrations remain within international safety limits, their patterns suggest early signs of trace-metal enrichment. Correlation analyses revealed strong relationships among acidity, organic matter, nutrient availability, and metal behavior, especially in Amanuke, showing how agrochemical use is gradually reshaping soil chemical interactions. Keywords Eco-Friendly Paving Blocks; Indigenous Materials; Sustainable Construction Materials Citation