Impact of Long-term Application of Agrochemicals on the Agro-Ecology of the Lower Anambra River Basin Southeast Nigeria.

Abstract

Information regarding the effect of application of Agro-chemicals on the soil environment of the lower Anambra River Basin is entirely lacking. A study was therefore conducted in the lower Anambra River Basin to assess the impact of long term use of Agrochemicals on the farm environment. The parameters studied were heavy metal levels [ercury (Hg), Copper (Cu), Arsenic (As), Lead (Pb), Chromium (Cr), Fe (Iron) Cadmium (Cd), Zinc (Zn), Manganese (Mn), and Nickel (Ni)] in the soil and run-off water, and soil and water microbial load. Soil and water samples were collected from the different locations of the river basin and analyzed for their content of these heavy metals.  Also the microbial loads of the soil and runoff water samples were determined using the standard plate count techniques. The Results of the analysis indicated that the heavy metals in the soils and runoff water were all above the permissive levels for agricultural and domestic purposes respectively, whereas the microbiological analysis indicated a reduction in the microbial load of the soil samples compared to standards.

Key Words: Agrochemicals application; Heavy Metals; microbial load; Soil; Runoff Water; River Basin.