Authors : J.C.Obi , A.O. Ogunkunle and O.O. Olatunji
Abstract: The nature, amount and distribution of iron (Fe) and aluminum (Al) oxides in a soil affects its charge characteristics and ion adsorption especially Phosphorus (P) sorption. Termites remove materials for termite nest construction and repairs from diverse locations but predominantly from the B-horizons of the profile which leads to the modification of soil properties and characteristics. The objective of the study was to determine the effect of termite infestation on the forms and distribution of Fe and Al oxides, hydroxides and oxyhydroxides in the soil. Two pedons with termite mounds (plot 1 and 2) and one without signs of present or previous termite mounds (plot 3) was sampled according to genetic horizons in both Mokwa and Kontagora area in the Niger State area of Nigeria (total of 6 pedons). Three mounds per plot was also broken and sampled. The termite species identified was macrotermitinae nigeriensis. The soils were classified as Arenic Kandiustox . The crystalline form of Fe and Al was higher than the amorphous forms in both the pedons and mounds. The crystalline form of Fe increased with depth in the non-infested soils of Mokwa but not in the infested. This increase with depth was also observed in plots plot 1 and 3 (infested and non-infested, respectively) and not in plot 2 of Kontagora. An indication of build up of crystalline form of sesquioxides on the surface of the infested soils. The means of crystalline and amorphous forms of Fe in the mounds were 7.39 and 11.27g kg 1, respectively in Kontagora and 7.60 and 10.84 g kg 1, respectively in Mokwa, while those of Al were 9.56 and 7.78 g kg 1, respectively in both Kontagora and Mokwa. These values fell within the range observed in the pedons especially on the surface and the surbsurface horizons. The observation in the infested soils of plot 1 and 3 of Mokwa and plot 2 of Kontagora created an indication that termite infestation may have affected the distribution of sesquioxides especially Fe oxides. This observed increase in the crystalline form of Fe oxides in the surface soil could lead to progressive deterioration of soil physical and chemical properties.
J.C.Obi , A.O. Ogunkunle and O.O. Olatunji , 2008. Extractable Iron and Aluminum Distribution in Macrotermitinae Nigeriensis Infested Guinea Savanna Alfisol. Agricultural Journal, 3: 345-348.