Design of a gravitational drip irrigation system

Abstract

The design and cost analysis of gravitational drip irrigation system was carried out in the Department of Agricultural Engineering Faculty of Technology University of Ibadan. This irrigation system was designed to suit farmlands not more than one hectare for small-scale farmers to irrigate vegetable crops. Before the design proper, preliminary studies were carried out and climatological data were collected, which was used to determine the rate of crop evapotranspiration used for the system's design i.e. 4.56mm/day for Ibadan climatic zone. The system has 100 laterals each of which is 50m long with each lateral having pressure-compensating emitters to distribute water and the mainline also 100m long. A model of the gravitational drip irrigation system was designed and tested. The test carried out on the model system shows that it can deliver 2.1-liter/hour of water with an operating head of 0.969m and the overall system's efficiency was found to be 94%. The efficiency of the system coupled with the installation and cost analysis shows that the system can be acquired and maintained by peasant farmers and still performs creditably well, when compared to the conventional drip irrigation system.