Variability of micronutrients status along topographic positions and toxicity potential of soils under rice cultivation in Niger State, Nigeria

Abstract

Micronutrients are important for good crop performance. There is limited quantitative data on the content and distribution of micronutrients in soils under rice cultivation in Niger state, particularly, on the soils of Baddeggi and Makusidi. To achieve this, soil samples were purposively collected along topographic positions (upper-slope, mid-slope, lower-slope and bottomlands) in the two areas. To assess the distribution of iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu), a total of sixty-four composite samples were collected at 0-15 and 15-30 cm depth and were determined by Atomic Absorption Spectrophotometry. The results revealed that the mean values of available Fe, Mn, Zn and Cu were 182.40, 41.90, 7.90 and 6.50 mg/kg for Baddeggi and 254.30, 275.13, 16.25 and 7.88 mg/kg for Makusidi respectively. The very high Fe and Mn in the study sites may lead to toxicity of these elements. The Cu and Zn were also relatively high, and their deficiencies are unlikely to occur in the study area.