PERFORMANCE EVALUATION OF PRESSURISED IRRIGATION SYSTEM

Abstract

A field experiment was carried out for the evaluation of drip online emitters of the 2, 4, 6 and 10 1ph capacity and effect of emitter discharge on soil, moisture distribution pattern in the experimental field of the Agricultural Engineering Section, College of Forestry & Hill Agriculture, Hill Campus, Ranichauri, Uttarakhand. The experiment was performed under gravity flow. The drip irrigation system was tested for its head-discharge relationship, uniformity coefficient, emission uniformity and manufacturing coefficient of variation. The study revealed that optimal pressure of 80, 90, 100 and 120 kPa is required for accurate discharge of drip emitters having capacities 2, 4, 6 and 10 1ph respectively. It was found that horizontal spread of water front was more in 10 1ph as compared to 6 1ph, 4 1ph and 2 1ph emitters and a disc pattern was observed in all type of emitters. To determine the soil moisture distribution, Iso-moisture content line was drawn. Iso- moisture content line shows that, moisture content was higher in top layers, which gradually decreased in downward direction up to 30 cm depth. Drip irrigation system is working well under gravity flow with sufficient pressure head and it was found that for deep rooted, medium rooted, shallow rooted crop 4 1ph, 6 1ph and 10 1ph emitters respectively can be recommended. Key. words: Irrigation, emitter, uniformity coefficient, manufacturing coefficient of variation, discharge, moisture distribution.