Abstract: Sub-species hybrid rice Liangyoupeijiu (two-line hybrid rice) and Xieyou-9308 (three-line hybrid rice) were selected as testing materials. The physiological characteristics of rice growth and development were studied by comparing the conventional flooding rice farming CFRF）with non-flooding rice farming ( NFRF). Results of the experiment showed that there were no differences as total leaf number and panicle initial development were concerned. At the same time, the period from sowing to heading was 4-8 days less of the NFRF than the CIRF, showing that the NFRF had comparative shorter reproductive duration. Larger total leaf area per hill, leaf area index and heavier root dry weight were observed on the NFRF. At the same time, the NFRF facilitates heavier and deeper root system. However, the NFRF is access to form a high biomass colony by large individual plant, and the dry matter accumulated after heading accounted for 40% of the total dry matter. Several disadvantages were also observed on the NFRF technique: (1) Less amount of root exude with lower zeatin content, and a lower respiration rate. (2) The flag leaf photosynthesis rate from filling stage to ripening stage decreased, and stomatal resistance increased as compared to traditional flooding irrigation. Some possible ways for increasing photosynthesis rate by improving physiological activity of plant during filling stage were also discussed.

Key words: Rice non-flooding rice farming, Leaf age, Photosynthesis rate, Root exude, Zeatin