32 September, 2010 International Agricultural Engineering Journal Vol. 19, No. 2 Design, construction and evaluation of low pressure and low cost drip irrigation system D. N. Sah 1 , R. C. Purohit 2 , Virendra Kumar 3 , A. K. Shukla 4 , S. K. Jain 5 (1. Department of Agricultural Sciences, Tennessee State University, Nashville, TN 37209, USA; 2 .Department of Natural Resources Management and Engineering, University of Connecticut, Storrs, CT 06268-4087, USA) Abstract: A manually operated low pressure low cost (LPLC) drip system was developed from locally available materials using KB pipes, KB pressure treadle pump, pressure drum with microtubes and medical infusion set. The field experiments were conducted and effect of various independent parameters such as vegetative growth, hydraulic performance, crop water requirements, water use efficiency, and cost economics were evaluated on different aspects for tomato and broccoli. The developed system has payback period of one season only with benefit to cost (B/C) ratio of 1.59 to 5.31. Thus, appropriate, affordable, divisible, accessible, low operation and maintenance cost, user friendly LPLC drip irrigation system is a good alternative for small land holders. Keywords: LPLC drip irrigation system, medi-emitter, divisible, vegetative growth parameters Citation: Sah D. N., R. C. Purohit, Virendra Kumar, A. K. Shukla, and S. K. Jain. 2010. Design, construction and evaluation of low pressure and low cost drip irrigation system. International Agricultural Engineering Journal, 19(2): 32－38. 1 Introduction India possesses 160 million ha of cultivated land (second largest in the world) and more than 70 percent of its population depends on agriculture. Out of 320 million work force of India, 170 million (53 percent) are employed in agriculture. The present productivity of food grains of irrigated farm area is 2-3 t/ha only as compared to 4-6 t/ha on research farms. Food production has become almost stagnant whereas the population of the country has exceeded 1,000 million people. Agriculture is by far the biggest user of water accounting for more than 70 percent of water utilization worldwide and 90 percent of water utilization in the developing countries. Irrigation is the largest consumer Received date: 2009- 05-25 Accepted date: 2010-08-25 Biographies: D. N. Sah, Ph.D. Scholar (IWME), CTAE, Udaipur, Email: deonsah@yahoo.com; R.C. Purohit, Professor, Head, SWE, CTAE, Udaipur; Email: purohitrc@yahoo.co.in; Virendra Kumar, Professor & Dean, CTAE, Udaipur; A.K. Shukla, Associate Professor, HORT, RCA, Udaipur; S.K. Jain, Assistant Professor, PFE, CTAE, MPUAT, Udaipur of fresh water. Therefore the aim should be to get optimal productivity per unit of water. Scientific water management, farm practices and drip irrigation method should be adopted wherever feasible (Alam and Kumar, 2001). The drip systems require intensive capital due to sophisticated technology. Therefore, it is beyond the capacity of the most farmers in India. If the drip system could be made affordable and within the reach of small and marginal farmers, it will definitely increase the productivity and income of the farmers and also, conserve the scarce precious water resources of the country. International Development Enterprises (IDE) has developed a low cost drip irrigation system, which has been extensively field tested to advance this technology accessible to small and marginal farmers. It has working head 0.5-3.0 m with 73-84 percent distribution uniformity (Polak et al., 1997). The objectives of present investigation were to develop and evaluate low pressure low cost (LPLC) drip irrigation system made from locally available materials and that would be adoptable and affordable for small land