Variability of micronutrient status and hazard potential in soils of six mapping units within Eastern part of Kogi state, Nigeria

Abstract

Micronutrient imbalance in some soils is a major challenge for cultivation of crops. Hence the need to assess their status and variability in agricultural soils. The aim of this research was to assess the micro-nutrient status, variability and hazard potential in some soils within eastern part of kogi state of Nigeria. Six mapping units, 2a, 17a, 19a, 19c, 21b and 22b from soil map of Nigeria, which dominated this region were chosen for the experiment. These represent wetland and savannah areas, with well drained and poorly drained loamy sand, sandy loam or sandy loam surfaces over sandy clay loam subsurface. Surface samples were collected in each mapping unit using soil auger. Samples were well-labelled in sampling bags and used for laboratory analyses of micronutrients. The results showed that the available zinc in the surface soils was moderate with exception of high values recorded at two points within the 2a mapping unit. The boron levels were low to moderate while moderate to high contents of iron were observed. The findings also showed that harmful effects of zinc were not likely in pedons 17a4, 19a1, 19a3, 19c2, 21b1, 21b3, 21b4 and 22a4 where the Hazard Quotient (HQ) values obtained were less than 1. Other pedons in Kogi East have likely harmful effects of iron as their calculated HQ values were greater than 1.