Mapping soil quality at Baifikrom small scale irrigration scheme in the central region of Ghana

Abstract

Continuous irrigation has been observed to degrade soil quality, through leaching of soluble and colloidal materials, development of saline conditions and breakdown of soil structure. Evaluating the quality of soils give information on the current soil condition as has resulted from previous soil management practices such as continuous application of fertilizer, and direct future management practices to sustain the soil ecology. Soil physical parameters (aggregate stability); Chemical parameters (pH, electrical conductivity, total nitrogen, extractable P, exchangeable K) and Biological parameters (organic carbon and microbial respiration) were selected to represent three soil indicators: soil degradation, nutrient cycling and crop productivity, respectively. These indicators were set to estimate soil quality. A raster interpolation for all the parameters and a reclassification of these raster maps was constructed in ArcGIS using all parameter maps to produce soil quality index (SQI). The highest SQI class ranged from 4.9 to 15.9 and the lowest class ranged from 0 to 1.5. Of the 11 plots, five had medium SQI while four had low SQI. Medium soil quality supports vegetable production; however, there is the need to improve pH and organic carbon content of the soils.