Design and simulation of an automated solar powered drip irrigation system for tomatoes at Busitema.

Abstract

Agriculture is the major economic activity in Uganda employing 65% of the total population. Majority of Ugandans practice rain fed agriculture despite the fact that since 1970, the rain fall trend is unreliable with increasing prolonged droughts. Only 14420 ha, is equipped for formal irrigation and Estimates of Uganda's spatial potential for improved irrigation vary from 170,000 ha to over 560,000, whereas the total potential arable area is 4,400,000 ha. The few irrigation schemes in place are. faced with problems such- as; poor management higher maintenance and operational cost and others are manual hence requiring a lot of energy. The purpose of the study was to develop an automated solar powered drip irrigation system that would utilize the abundant sunshine in Busitema to power an irrigation system for tomatoes with the purpose of reducing poverty levels, food scarcity and malnutrition. Since the intensity of solar radiation is complementary to the water demanded 'by the crop, solar energy is available at the site, cheap in the long run due to. low maintenance and operating costs, environmental friendly and a renewable energy. Automation saves time since there is no need for supervision, saves water and energy since watering is done. only when there is need, reduces labour demand. The project involved collecting climatic data, soil data, crop data, water supply data and a topographica1 data using methods such as oral interviews, laboratory analysis and using a GPS, drip irrigation designing, pump selection, solar sizing, economic analysis and simulation. Economic analysis on the project was carried out for a period of 10 years on the automated PV solar powered system in comparison with PV solar powered without automation and diesel pump irrigation systems The accumulated total costs were $17540.75, $13704.377, $ 14638.4 for diesel pumped PV without automation and automated PV solar powered irrigation systems respectively. From the three alternatives, it is seen that PV solar. powered without automation has the least expense for the life span of the project but PV solar powered with automation. is considered to be the best because of other advantages such as; saving water, energy, and reduced labour demand since watering is done only when there is need.