Soil Quality Of Irrigable Lands Of Irrigation Schemes In Northern Ghana

Abstract

This research was carried out in the Tono, Vea, Doba Libga, Bontanga and Golinga irrigation schemes in the Upper East and Northern Regions of Ghana to assess soil quality of the irrigable areas. The irrigable areas of the schemes were divided into three blocks namely; upstream, midstream and downstream for soil sampling. Three (3) composite soil samples each were taken at 0 – 30 cm depth in each stream of each scheme. The findings indicated that the pH of the soils from all the schemes except Libga were within 5.2 – 6.4, whilst the soils of Libga scheme have average pH of 8.8. Electrical conductivity or salinity in the schemes except Libga ranged from 1.2 – 39.3 μS/cm whilst the Libga scheme recorded salinity levels of 317 – 4,106 μS/cm. The mean ESP or sodicity of all the schemes except Libga ranged from 1.0 – 4.8 % with the Libga scheme recording levels of 8.5 – 30 %. Mean sodium values of the Libga scheme averaged 440.7 mg/kg whilst the other schemes recorded averages ranging from 47.3 – 71.0 mg/kg. The mean CEC concentration for the Libga scheme was 7.9 cmol/kg with the other schemes recrding between 7.9 – 19.5 cmol/kg. The irrigable areas of Tono, Vea, Doba, Bontanga and Golinga schemes were noted to be environmentally stable recording an index of 95 – 100 %. The irrigable area of Libga scheme however recorded an environmental stability index of 86 %. Excessive application of inorganic fertilizers should be avoided. The management of the schemes especially the Libga scheme should periodically and regularly monitor pH, salinity and sodicity levels in the irrigable areas.