Abstract
PHYSICO-CHEMICAL PROPERTIES AND DISTRIBUTION OF AVAILABLE BORON IN SOILS ALONG TWO OPPOSITE TOPOSEQUENCES IN UNIVERSITY OF ABUJA

This research work is aimed at studying some physico-chemical properties of the soil and the distribution of Boron in the soil along two opposite toposequences in the Teaching and Research Farm of University of Abuja. To achieve this goal, a two opposite toposequences were selected during a Reconnaissance survey of the area. Soil samples were collected and analysed for physico-chemical properties and some micronutrients. The result indicated that the soils of the area are strongly acidic (pH in water 4.70 to 5.80), while the soil texture is uniformly sandy loam at the surface and sandy clay loam and clay loam in the subsurface. The electrical conductivity ranges between 0.040 – 0.100 dS/m. Organic matter was high with a range of 1.11 to 5.08 % while Total nitrogen and phosphorus were rated moderate with values ranging from 0.105 to 0.210 % and 12.25 to 38.50 ppm respectively. Boron was in the range of 1.22 - 1.83 mgKg-1 with a mean value of 1.58 mgKg-1 with a mean value of 1.58 mgKg-1 for the composite sample. Within the profile pits, the values range from 0.63 to 2.64 mgKg-1 with a mean value of 1.63 mgKg-1. Boron was found to increase in the lower soil horizons than at the surface. Generally, boron was found to be adequate for crop production in the soils. It was recommended that there is no basis for further application of any micronutrients in the soils because they are highly available and poses the danger of toxicity