A study on irrigation management practice strategies of paddy rice under shortage environment

Drought is a natural event that cannot be avoided. In recent years, due to extreme climate events, occurrence of drought has grown in frequency and intensity. Developing shortage of irrigation water management strategies to reduce the impact on food production caused by drought is a globally important issue. The purpose of this research is to discover the relationship between the productivity of paddy rice and water efficiency of the irrigation water under different cultivation time, crop growth stage, and irrigation interval by field experiments (from January 16^th 2011 to February 16^th 2012) at irrigation center in Chia-Nan Irrigation Association. The goal is to attain the degree of drought tolerance and save irrigation water, in order to assess the treating effects on the growth interval, agronomic traits, crop water requirements, irrigation timing, field irrigation requirement, and water productivity of paddy rice without compromising on yield. This information will lead to the minimum water requirements under different drought conditions. These requirements can also serve as the foundation for the irrigation bureau to implement a feasible irrigation ration policy. The result of this research shows that, with the variety cultivation intervals, the water shortage during the first-season paddy rice, the growth interval, evapotranspiration, and field irrigation requirement were reduced. When the yield and water saving for irrigation are considered at the same time, it is recommended to adjust the cultivation time for the drought in spring planting on February 16th with an irrigation interval of 7 days is recommended for paddy rice during the heading stage, through which the amounts of water can be saved for about 23.3%~30.5%, and the yield is only slightly influenced. The results can be applied to irrigation water management during drought period in spring and adaptive to climate change.