THE USE OF GEOGRAPHIC INFORMATION SYSTEM (GIS) TECHNOLOGY FOR SPATIAL ANALYSIS AND MANAGEMENT OF SOIL ORGANIC CARBON

Abstract

Precision agriculture that maximizes crop yields and reduce the cost of production can be achieved by spatial analysis of soil properties using Geographic Information System (GIS) technology. The spatial variability of soil organic carbon (SOC) in relation topography and site-specific management of organic material to increase the SOC using GIS technology was carried out on a 51 ha arable farmland in Minna, Nigeria. The field was partitioned into 50 m x 50 m grid or subplots numbered 1 to 204. Out of these subplots, forty were selected using stratified random sampling technique, for soil sampling at 0-20 cm depth, and the sampling points were geo-referenced. Field data collected and laboratory analysis results were imputed into computer software, SURFER 11 for interpolation and digital mapping. The SOC ranged from 1.44 to 13.27 g kg-1 and rated low to medium, with a low coefficient of variability (CV) of 6.35 %. Topography of the field ranged from 185 to 213 m above sea level (asl) with a medium CV of 16.23 %. There was no significant correlation between SOC and topography. Based on the SOC content of very low, < 5 g kg-1 and low, > 5 g kg-1, two relatively homogenous units designated MU1, covering 35.06 ha and MU2, covering 15.94 ha, were obtained. The site-specific application of organic materials to the two units reduced the quantity required by blanket application to the whole field by about 16 %.