SEASONAL CHEMICAL SPECIATION AND POTENTIAL MOBILITY OF HEAVY METALS IN THE SURFACE SOIL OF SOME POULTRY FARM ESTABLISHMENTS OF OSUN STATE, SOUTHWESTERN NIGERIA

摘要

This work examined the presence, availableness and mobility of metals in chosen poultry farm soils areas samples from Osun State. Metals in the stratified soil samples taken in both seasons were in sequence extracted into five phases and content of the extracted metals was conducted utilizing Flame Atomic Absorption Spectrophotometer. Quality control measures involved blank test, spike recovery test and calibration of standards. Descriptive and inferential statistics were adopted for data analyses The range of metals extracted from each of the five soil geochemical phases in mean percentages for both seasons are in this manner: carbonate bound (0.84-19.94), exchangeable (8.43-18.84), Fe-Mn oxide (13.95-21.18), organic matter (21.43-34.14) and residual (15.45-41.48). Potential metals in the examined soils (mgkg~(-1)) varies between 3.56-1181.62, 0.05-2.98, 10.72-75.06, 40.38-640.52, 3.32-96.69 and 9.80-219.12 for arsenic, cadmium, copper, iron, lead and zinc, while mean % mobility factors of all the metals in both seasons examined were ranged between 30.54-33.04, 33.29-34.49, 37.11-38.74, 15.37-17.58, 35.02-35.31 and 24.48-27.02 for As, Cd, Cu, Fe, Pb and Zn. In the poultry agro-ecological agriculture, values of metals in available forms do not vary statistically in both seasons. Nevertheless, bulk of the sampled metals have high abundance in residual and organic matter phases and for this reason, may not present ecological threat inasmuch as their overall fairly minor availableness and MFs of the metals in the examined soil.