PERFORMANCE EVALUATION AND IMPROVEMENT MEASURES OF WATER PRODUCTIVITY FOR MSANGE IRRIGATION SCHEME IN TANZANIA

Abstract

Performance evaluation is an activity that supports planning and implementation procedure of irrigation projects. The motivation behind performance is to accomplish an effective and viable utilization of resources by giving important criticism to the scheme management. Therefore, the objective of the study is to evaluate the performance of Msange irrigation scheme at Singida District in Tanzania employing a various performance indicators. The scheme has a command area of 10 ha served by drip irrigation system benefiting about 58 farmers. To accomplish the set objectives both field and secondary data were collected such as discharge measurements, soil samples, irrigation application, delivered volume of water to the field, meteorological data, cropping pattern, yields, crop prices, irrigation cost, irrigated land, cost of production and O&M costs. Water supply, agricultural outputs, economic performance and environmental quality indicators were evaluated in this study. To facilitate the assessment three main crops were evaluated, for this case maize, onion and tomatoes. The specific indicators for water supply performance are RWS and RIS and WDC. The results for RWS, RIS and WDC were found to be 0.93, 0.92 and 1.79 respectively. The analysis of agricultural outputs, outputs per irrigated cropped land and command area were found as 2,179.41 and 2,799.50 US$/ha respectively, and the corresponding outputs per unit irrigation supply and water consumed was 0.51 and 0.46 US$/m3 respectively. The results from economic performance on BCR and O&M fraction depicted the value of 1.01 for BCR and 0.65 for O&M fraction. This indicates that Msange irrigation project is worthy undertaking for supporting farmers’ livelihood. To evaluate environmental quality, SQI was used by integrating chemical and physical parameters. The soil type from the study area is silt loam with an overall SQI of 0.57 making the soil to be rated as medium quality. In conclusion, the determined overall performance index of Msange irrigation scheme is 69 % which show a satisfactory performance, rated as medium to high performance. However with this index, improvement is needed to further increase performance and water productivity so that more benefits are obtained. Among the measures to improve performance and water productivity include proper irrigation scheduling, correct estimation of water demand, regulating water delivery, optimizing irrigation water, improving agronomic practices and soil quality management