Assessment of water quality for irrigated rice production as affected by a cluster of auto mechanic workshops upstream

2015

English

In the rice irrigated field, located at the Central Agricultural Station of Kwadaso in Kumasi in the Ashanti region of Ghana, the main sources of water for the crop are rain and stream water for irrigation which takes it source from clusters of auto mechanic workshops and car washing bays. Due to possible contamination of the stream water it was necessary to assess the levels of some selected contaminants. A total of fifteen water samples were collected from the stream and the irrigated field (three from each location) and analyzed for pH ranging from 5.61-6.25, Electrical Conductivity of irrigation water (ECiw) 0.06-0.25ds m-1, Total dissolved Salts (TDS) 68.9-143.1mg l-1, HCO3- 99.34-140.00)mg l-1, Sodium Adsorption Ratio (SAR) 0.38-0.49, Soluble Sodium Percentage (SSP) 26-40, Residual Sodium Concentration (RSC) 2.19-3.09, Kelly Ratio (KR) 0.30-0.55, in addition, some selected heavy metals which are normally concentrated in such areas. The analyzed chemical constituents and its corresponding values were compared with international standards. The upper course of the study area had the highest levels of the chemical constituents in water. Salinity and other chemical constituents showed a decreasing trend towards the lower course of the study area. The presence of the auto mechanic workshops and car washing bays influence the quality of the stream. The Water from the stream was identified to be suitable for irrigation. Further studies on the seasonal variations of the water quality parameters are highly recommended in the study area.

Adjei, E. O.; Sadick, A.