Feasibility study of gravity-fed drip irrigation system on hilly terrace land in mid-Himalayan regions

An experiment was conducted in 2003–2004 to evaluate the feasibility of gravity-fed drip irrigation on terrace land under sub-humid climate of Mid-Himalayas. In the field study, an attempt has been made to evaluate the performance of the drip irrigation system based on the uniformity of water distribution & wetting pattern in hilly terraces. Drip system was also used for optimizing the water requirement of tomato crop by setting up Randamized Block Design (RBD) with six treatments consisting of four levels of irrigation; 40%, 60%, 80%, & 100% of full irrigation through drip method, check basin (full irrigation) and control(rainfed), with 3 replications. Analysis revealed that Emission Uniformity (EU) and Statistical Uniformity (SU) of drip system were 68% and 84%, respectively. Wetting pattern showed that moisture concentration was high within 0–15 cm from the emitter on the surface, and significant rise in moisture was observed when water application exceeded 4 litres/hr of flow volume. Growth parameters of tomato, viz; no. of primary branches, fruit diameter (cm) and days to 50% flowering were recorded maximum in T₃(60% of full irrigation), i.e 8.3,7.1 and 25.5, respectively. Yield of tomato achieved from the T was maximum (25.97 t ha⁻¹) and water saving was registered 40% over full irrigation method. Besides, Water Use Efficiency (WUE) in same treatment was found to be highest (92 gha-mm). The study indicates that in hilly terraces, gravity-fed drip irrigation is a cost effective irrigation method and able to conserve the scarce water resources, minimizing soil erosion and thus enhancing the vegetable productivity and maintaining the environmental quality.