Soil physicochemical properties as influenced by persistent herbicide weed control in some communities in Ondo State, Nigeria

Abstract

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.

Seasonal variations in the levels of glyphosate in soil, water and crops from three farm settlements in Oyo state, Nigeria

“…Similar report by Ref. [ 36 ] revealed that some communities in Ondo State, Nigeria that have been exposed to herbicides had soil pH ranges from slightly acidic to neutral. So, at this pH level, less pesticide will be absorbed at the soil's surface.…”

“…The soil detected inside the examined sites belonged to the textural class of sandy-loamy. The soils' high concentration of sand may be a result of Nigeria's typically sandy, humid tropical soils [ 42 ].The sandy nature of the soil encourages the leaching of numerous soil properties into the groundwater, rivers, lakes, and streams nearby during the rainy season when herbicide treatment occurs [ 36 ]. Soils that have a significant amount of sand particles are referred to as Sand, loamy sand, or sandy loam soils and are considered to be coarse in texture.…”

The Physicochemical Properties and Microbial Populations of Nicosulfuron Treated Soil in Yola, Adamawa State, Nigeria

“…This is because the use of the herbicides has effectively aid in controlling and checking the growth of weeds, which are the major competitors to crops for soil nutrients and water. However, some of these herbicides were reported to have significant effect on both physicochemical and microbial components of soil [4,5]. A significant effect of herbicides like glyphosate, triclopyr and fluroxypyr on soil physicochemical properties that include pH and soil nitrogen was reported by [6].…”