Effects of different irrigation modes on the yield and water productivity of rice

With hybrid rice cultivars "Liangyou Peijiu" and "ⅡYou 725" as experimental materials, the yield, quality and water productivity of rice growing in weighting lysimeters under four irrigation modes were analyzed. Compared with continuous flooding irrigation, the water consumption of "Liangyou Peijiu" in growth stages under intermittent irrigation, semi-dry cultivation and dry cultivation decreases 10.65%, 25.70%, 34.68%, respectively, while yield increases 7.38% and decreases 17.29%, 41.01%, respectively; the water consumption of "ⅡYou 725" decreases 12.49%, 22.08%, 32.24%, respectively, while yield increases 8.54% and decreases 20.00%, 46.43%, respectively. The water productivity is the highest under intermittent irrigation, relatively higher under semi-dry cultivation, but relatively lower under continuous flooding irrigation and dry cultivation. Compared with other irrigation treatments, the milled rice rate, head rice rate and grain length under intermittent irrigation increase, while the chalky rice and chalkiness decrease. With the reduction of water consumption, the amylose content of rice grain decreases, but the gel consistency and protein content increase. Intermittent irrigation will be a favorable irrigation mode for the paddy rice planting in the south China.