Variability of Soil Extractable Micronutrients in the Upland and Lowland Topoposition Soils of Gubi Village, Bauchi State, North Eastern Nigeria

The aim of this study was to assess the variability of extractable micronutrients in the varying topoposition soils of Gubi village. Four profile pits were dug at each of the designated topopositions making a total of eight profiles. The profiles were dug at the crest, upper slope, middle slope and valley bottom positions of the two toposequences and were named URFGU1, URFGU2, URFGU3 to URFGU4 and URFGL1. URFGL2, URFGL3 to URFGL4 for upland and lowland respectively. The content and profile distribution of extractable micronutrients copper (Cu), Zinc (Zn), manganese (Mn) and Iron (Fe) were extracted using 0.1 m HCl solution and determined using atomic absorption spectrophotometer (AAS) at appropriate wavelengths (Ca at 247 nm, Zn at 214 nm, Mn at 279 nm and Fe at 248 nm. Data generated was statistically analyzed using analysis of variance in nested experimental design. The significance of difference between treatments was determined using fishers LSD. Means that were significantly different were separated using the Least Significant Difference (LSD). The result reveals that Copper (Cu), iron (Fe) and manganese (Mn) varied significantly due to location. Iron and manganese were significantly higher in the upland soil (47.35 and 47.50 mg/kg respectively) than in the lowland soil (17.67 and 27.38 mg/kg respectively). The lowland soil had significantly higher Cu (1.31 mg/kg) than the upland soil (0.37 mg/kg). Zinc (Zn) did not vary significantly due to location however the lowland soil (0.86 mg/kg) had a higher Zn content than the upland soil (0.26 mg/kg).