Soil physicochemical properties as influenced by persistent herbicide weed control in some communities in Ondo State, Nigeria
This study identified areas where different types of herbicide were used for municipal weed control in selected residential communities in Akure, Akungba-Akoko and Owo in Ondo State, Nigeria. A survey of the communities was carried out to identify sites maintained with herbicides (test sites) and those without herbicide history (control sites). Composite soil samples collected from each site were analyzed using standard laboratory procedures for the determination of selected soil physical and chemical properties. The data obtained were subjected to statistical analysis of variance (ANOVA). Results obtained indicated that the soil texture of the study sites were mostly sandy loam while pH ranged from slightly acidic to neutral. Significant differences (P < 0.05) were observed in the organic carbon (OC) contents of soil samples from Owo as against the samples from Akure and Akungba-Akoko though Owo had the highest OC (24.48 ± 9.36 g kg-1) followed by Akungba-Akoko (21.21 ± 10.36 g kg-1) and Akure (18.10 ± 7.75 kg-1) which was the lowest. However, no significant differences (P < 0.05) were observed in the values of the micronutrients and exchangeable cations across all the sites. Conclusively, application of herbicides to weeds did not have significant effect on the soil fertility (in all the sites) in the short run (2013 - 2015) but more aggressive application could have deleterious effects in the long run because leaching is encouraged as a result of the sandy nature and low organic carbon content of the soil in the study areas.
Keywords: Herbicides, weeds, soil, physicochemical properties