MICRONUTRIENT DYNAMICS IN RELATION TO SOIL PROPERTIES IN ARABLE SOILS OF RIGACHIKUN-KADUNA, NORTHERN GUINEA SAVANNAH, NIGERIA

Abstract

The research was conducted within January 2020 – January 2021 at the arable soils of Rigachikun-Kaduna, Northern Guinea Savanna and intended to study the micronutrient dynamics and relationships with some studied soil properties. Previously harvested maize, cowpea and rice soils (designated as Locations A, B and C respectively) were delineated, and three profile pits dug in each along the line of transect of about 100 m apart. A total of nine profile pits were dug in the three delineations and samples collected from each pit according to their horizonations. The use of Digital Elevation Model (DEM) was employed to study the terrain characteristics of the location. Major micronutrients investigated were Cu, Fe, Zn and Mn. Virtually all micronutrients decreased down the profile in all studied locations with Cu and Zn displaying an irregular trend in all pedons of rice harvested soils in location C. Also Fe rather increased in pedon 1 of location C as well. Cu had positive and non-significant correlation with other micronutrients (Fe and Zn), it however had a significant relationship with Mn. With respect to other soil properties investigated, Cu maintained a negative non-significant correlations. Fe had a positive and highly significant correlation with Mn and Zn. Also, Fe had a significant and negative correlation with organic matter but positive with available phosphorus. Fe was positively but non-significantly correlated with other soil properties such as clay, Ca, Mg, and total exchangeable bases (TEB). There was however, a non-significant and negative correlations of Fe with soil pH, K, Na as well as total exchangeable acidity (TEA). Mn only had significant and positive correlations with all other micronutrients (Cu, Fe and Zn) but non-significantly correlated with other soil properties. Micronutrients were all low to a deficiency level considering their critical limits in the tropical soils. Low organic matter content of soils of Rigachikun may have contributed to low micronutrient reserve of the soils. Activities that will conserve organic matter such as accumulation of litter from harvested crops and alternative means of cattle rearing such ranching rather than freelance grazing should be employed, as efforts to replenish micronutrients through fertilization has not yielded the desired results.