This experiment study is to research for how the reductive irrigation water application affects the growth and the production of rice. The test was held on the first and second crops in the year of 1996 with the different irrigation treatments as for the field experiment. The entire growth period of the rice can be divided into three stages as follows:1.Nutritive growing period: sprout from seed till being put forth budding of the ears are well ramified. 2.Generative growing period: from the budding of young ears ramified well till heading rice. 3.Maturity period: from heading till ripening stage. According to a literature report pointed out that, during the period of reproductive growing period, from the young ears tilling stage till the heading period, these two periods the rice gives the most sensible to the water and will thus effect the production. Therefore, in this study during this time used different kinds of irrigation treatment for the field experiment, aiming at the water amount applied for rice irrigation to see whether the growth and production yield will be effected or not, for the reference of the arrangement of water saving irrigation during drought season in future. The test result on the 2 consecutive crops is as follows: In the first crop of rice field, the adopted test was 2 kinds of treatment with 3 kinds of overlapped items. Besides, 95% of reliability was used to examine the difference between the normal irrigation and the water saving sprinkler irrigation. Then, it is known from the Table 4.21, there was no appearant effect between the numbers of stub and head of rice, however, there was an appearant difference between the 1000-grain-weight of rice and the ripen ratio, numbers of grains per head of ear and the production yield, etc. On the production aspect, the variety of Shin-chu No.64 in sprinkler using district was 84.8% of the normal irrigation district which is 15.2% lower. The variety of Kao-hsiung No.142 in the same irrigation district was 87.2% of the normal district which was 12.8%lower. In this time, the experiment being conducted in sprinkler irrigation district was planned to use 30% of water-less-ratio, but the actual average water-lacking-ratio was 28.25%. In the second crop experiment, 3 kinds of treatment were used, in which 2 kinds were overlapped. In the watered dry district, the water supply ratio was 75% of the normal district, which means 25% less of water. On the rice variety aspect in this crop, this was changed to use the Hsin-chu No.64 and the Tai-nan No.67 varieties for plant. Every variety was distributed to three different districts, i.e. a. watered dry district by sprinkler irrigation, b. watered dry district by flooding irrigation, and c. normal by flooding irrigation, and use 95% reliability to check their agricultural technologies. The varieties of the Hsin-chu No.64 and the Tai-nan No.67 have a little different. There is no appearant difference in the height of stub, weight of 1000 grains of rice and ripen ratio. But the numbers of head and the numbers of grains per head have a remarkable difference. On the production yielding aspect, the Hsin-chu No.64 variety in the watered dry sprinkler district yields 91.5% of the normal district, in the watered dry district by flooding irrigation, it yields 86.8%. The variety of the Tai-nan No.67 in the watered dry district by sprinkler yields 95.4% of general district, in watered dry district by follding irrigation yields 92.4% of general district. Analyse into the reason, possibly because of fewer rainfall, so the lack of water did not show remarkable effect.
