Assessment of irrigation water requirement and water productivity of rice under ratoon and conventional cultivation under climate change scenarios: a case study of the Phraphimon irrigation project area in Thailand | |
| Author | Pannavit Fuangthong |
| Call Number | AIT Thesis no.WM-18-20 |
| Subject(s) | Irrigation water--Thailand Climatic change--Thailand |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-18-20 |
| Abstract | Ratoon cultivation has been used over 50 years by farmers from many countries. However, in Thailand, ratooning technique is utilized only in few areas namely: Nakornphatom province, Pathumtani province and Chiangmai province of Thailand. It is the fact that ratoon crop requires less of growth duration and cultivation cost because the rice from their stubble of conventional crop (maincrop) after done harvesting. Although shorter growth duration, many research’s claim that ratoon crop requires less of irrigation water. Consequently, the goal of this thesis is not only to determine the difference of irrigation water requirement (IWR) and crop water productivity (CWP) by compare between main crop that grown by conventional technique and ratoon crop, but also to determine both parameters under climate change impact on both techniques. Moreover, survey part is also important for this study. To compare both techniques, this thesis is studied on present opportunity of ratoon technique through the questionnaire from farmers in Phapimon irrigation project, located in Nakornphatom province of Thailand. From six previous crop data, the CROPWAT model was shown that IWR of ratoon crops was less than conventional crop around 35-51 percent or around 200-500 mm. While comparing conventional crop at the same cultivated period, ratoon crop can save around 15-30 percent or around 60-100 mm. For future analysis, this study will be related to three crops. First crop is conventional crop in dry season (February onward), second crop is ratoon crop in wet season (June onward) and third crop is conventional crop at ratoon crop period. From the result, in upcoming future, IWR of three crops will be slightly increased around 1 percent in case of RCP 4.5 and 8.5. Next, in mid future, the irrigation water requirement will be increased around 2-4 percent. At last, in far future, the IWR will be increased around 3-10 percent. CWP is a necessary parameter to compare water use efficiency. From the given data, CWP of ratoon crop is around 1.3-1.5 kg/m3, while conventional crop is around 1.12-1.77 kg/m3. When compared between main crop and ratoon crop, CWP of ratoon crop was higher than main crop around (0.18-0.22 kg/m3). In the future, CWP of all crops will be decreased around 0.02 and 0.04 at next future period in case of RCP 4.5 and 8.5, respectively. Based on farmers surveyed, most of farmers claim that ratoon cultivation requires less of requirement, such as, overall cost, water use, growth duration and weed management. On the other hand, ratoon crop was less than conventional crop around 20%. Most of the ratoon farmers have confirmed that they will continue use ratooning technique. In addition, ratoon cultivation is not proper in wet season because the stubble will be flooded and it cannot grow properly, as a result, the yield will dramatically decrease to 50%. At last, in draught situation ratooning technique can be used as a one of measurement for rice farmers instead of stop cultivation. |
| Year | 2018 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-18-20 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Shrestha, Sangam ; |
| Examination Committee(s) | Datta, Avishek;Duc Hoang Nguyen; |
| Scholarship Donor(s) | -; |