Spatial and Geo-Statistical Analysis of Variability of the Soil Particle Size Distribution in River Wudil Floodplain, Kano State, Nigeria

Abstract

This study was conducted to analyze the spatial and geo-statistical variability of the soil particle size distribution in River Wudil floodplain, Kano State, Nigeria. From the study area, 150 soil samples were collected at a depth of 0-30 cm, by 100 × 200 m regular, using systematic grid sampling technique. The soil particle size distribution (sand, silt, and clay) were measured in the laboratory using the Bouyoucos hydrometer method. After data curation, classical and geo-statistical analyses were used to describe soil properties and spatial correlation of soil characteristics. Spatial variability of the sand, silt, and clay particles was quantified through semi-variogram analysis and the respective surface maps were prepared through ordinary Kriging. The result revealed that clay contents have moderate spatial dependence, with nugget/sill ratios between 25-75℅, while sand and silt have weak dependence with nugget/sill ratios of greater than 75%. The result showed that all the soil samples varied considerably all over the studied area. The sand distribution was observed to show the least level of variability, while the silt and clay distribution was observed to show moderate variability among the three measured parameters. In conclusion, the spatial distribution of the particle size distribution varied across the study area. The study recommends integrated soil fertility management, combining organic and inorganic fertilizers, due to moderate spatial dependence on clay content. A site-specific nutrient management strategy, accounting for structural and random factors, is suggested to address moderate spatial variability in silt and clay contents.