ASSESSMENT OF DEEP TUBEWELL DRIVEN IRRIGATION SYSTEM IN THAKURGAON SADAR THANA

Abstract

Studies were conducted in Thakurgaon area during T. Aman season 2016-2017 to Boro season 2017-2018 in order to suggest some important criteria related to improved water management practices for rice based cropping system using deep tubewell. About hundred percent farmers of the study area reported that they received enough water from the respective DTWs for different crops. Most of the farmers of the study area used earthen channel as a distribution system. The actual discharges of three selected DTWs in three locations were 56 lit/s for 20 to30 HP engines. Appropriate pump size should be used to reduce irrigation cost. There were no conveyance loss in buried pipe line. The economic performance of supplemental irrigation by using buried pipe for T. Aman and Boro rice cultivation with irrigated condition is highly profitable. For improved lined water distribution system, saving of irrigation water and distribution time and increase of irrigated area respectively were 13-18%, 25-29% and 46-51% in comparison to that of earthen channel. Similarly for buried pipe distribution system, the above parameters were respectively 98-99%, 56-61% and 80-82% in comparison to that of earthen channel system. To obtain greater conveyance efficiency buried pipe and improved compacted earthen channel should be used to distribute water in the irrigated crop fields. The study shows that continuous standing water is not necessary for optimum yield of rice. Moreover, without sacrificing much yield, about 41 percent and 37 percent of valuable irrigation water can be saved over treatment T1 (continuous standing water) by practicing the treatment T2 (Irrigation depth of 7 cm after 3 days of dissapearance of standing water) respectively. For optimum utilization of irrigation water, water saving technique like irrigating after 3 days of standing water as suggested in this study, should be followed properly.