The potentially available and total micronutrient status in soils of derived savanna ecology of Oyo State, Nigeria were assessed and compared with standard critical values in soils. Soil samples were collected from a land measuring 285m2 on a line transect with the aid of a stainless soil auger. The sampling depths were 0 -15 cm, 15 – 30 cm, 30 – 45 cm and 45 – 60 cm respectively. The Physico-chemical properties and micronutrient content of the soil were determined using standard methods. The mobility factor of the micronutrients revealed the following trends Zn > Fe > Mn > Cu. In all, the concentration of Mn was relatively constant irrespective of the soil depth. This study revealed that the micronutrients (Fe, Mn, Zn, and Cu) were adequate and well supplied in the soils of the area, and therefore, deficiencies of the elements are quite unlikely. Generally, the soils contained Fe, Mn, Zn, and Cu above the critical level for crop production. The application of organic matter would help to improve the overall fertility of the soil. Activities that hastens up mineralization of organic materials should be minimized in managing soil health for optimum nutrient availability. Soil testing is recommended before fertilizer use to prevent nutrient imbalance or toxicity.
Soil productivity improvement under different fallow types on Alfisol of a derived savanna ecology of Nigeria
