Characterization and classification of greenbelt soils in Yambio and Nzara counties, Western Equatoria State, South Sudan

Abstract

The objectives of this study were to characterize, classify and evaluate the potential and constraints of the soils of Sakure and Nginda Payams in Nzara and Yambio counties in the Greenbelt zone of Western Equatoria State, South Sudan. Ten soil pits were dug, described and sampled based on FAO soil profile description guideline and samples were analysed using standard routine lab analyses for physical and chemical properties. Data generated were analysed statistically using the coefficient of variation (CV) and correlation. Results showed that top and subsoil were dominated by sandy clay loams. The soil reactions were strongly to slightly acidic (pH = 5.4 - 6.7). The most limiting nutrients were P and N. SOC was highest in the top soil and consistently decreased with depth, the CEC was low (4 - 14.4 Cmol kg -1 ). The soils were classified into six major soil types: Ferralsol, retisols, acrisols, umbrisols, fluvisols, and chernozems. The soils have poor inherent soil fertility. It is recommended that further soil survey be carried out in the Greenbelt zone and to conduct more research to determine the type of soil fertility management feasible.