ASSESSMENT OF SPATIAL VARIABILITY OF SOME SOIL PROPERTIES AT CENTRE FOR DRYLAND AGRICULTURAL RESEARCH FARM BAYERO UNIVERSITY KANO.

Abstract

The research was conducted at the Centre for Dryland Agricultural research farm with the aim of assessing the spatial variability of some soil properties and the degree of relationship between such properties. The boundary of the areas was delineated and georeferenced in ArcGIS environment, followed by digitization and creation of the shape file to represent the area. The fishnet of ArcToolbox was used to generate grid of 50 x 50 meter, and the centre of each grid was extracted and imported into Geographical Positioning System (GPS) to locate each of the sampling point. Composited soil samples were collected at the depth of 0-20cm, and the samples were prepared and analyzed based on the standard laboratory procedures.  The results were subjected to descriptive statistic and geostatistics to generate the spatial representation of each parameter of the location.  The result revealed that there was moderate variability in Clay, Iron and Cupper, while sand, silt, electrical conductivity, Zinc had a strong coefficient of variation (>75%).  Highly Significant negative relationship was observed between sand, clay and silt, and highly significant positive relationship was also observed between clay and silt.  Sand dominated all the mineral fractions and the content of micronutrient were rated moderate to high. Strong positive relationship was obtained between all micronutrient, except zinc and iron. Simple and ordinary krigging methods were used for the interpolation, with stable and exponential as best models for all the variables, except iron. Weak to moderate spatial autocorrelation was observed between all the parameters. Soil amendment should be used to improved the water holding capacity of the soil, and application of fertilizer bearing micronutrient should checked to reduced toxicity of these nutrients in the soil.