不同灌溉方式对水稻生物学特性与水分利用效率的影响

以杂交水稻两优培九为试验材料,利用测坑栽培条件，比较了4种灌溉方式下的水稻生物学特性与水分利用效率.结果表明，与淹水灌溉相比，间歇灌溉叶面积指数大，叶片光合速率高，蒸腾速率较低，叶片水分利用效率高；半干旱栽培叶片水分利用效率相对较高；干旱栽培叶面积指数小，叶片净光合速率和水分利用效率降低，且后期叶片早衰.间歇灌溉、半干旱栽培和干旱栽培比淹水灌溉分别节水8.75%、17.96%和29.69%；产量分别增产24.02%、减产5.07%和减产38.93%；水分利用效率以间歇灌溉最高，半干旱栽培次之，淹水灌溉和干旱栽培较低.间歇灌溉下稻粒的整精米率、精米率、粒长均高于其它处理，但垩白粒率和垩白度低于其它处理；随着稻田耗水量的减少，水稻的直链淀粉含量降低，而胶稠度和蛋白质含量提高.试验结果表明间歇灌溉为南方稻区较适宜的灌溉方式.

Effects of different irrigation modes on biological characteristics and water use efficiency of paddy rice

With hybrid rice cuhivar Liangyou Peijiu as test material, this paper studied its biological characteristics and water use efficiency under effects of four irrigation modes. Compared with continuous flooding irrigation, intermittent irrigation increased the leaf area index, photosynthetic rate and water use efficiency, and decreased the leaf transpiration rate. Semi-dry cultivation increased the leaf water use efficiency, while dry cultivation decreased the leaf area index, photosynthetic rate, and water use efficiency, and induced the leaf senescence in later growth period. Under intermittent irrigation, semi-dry cultivation and dry cultivation, the water consumption of paddy rice was 8.75% , 17.96% and 29.69% lower, and its grain yield was 24. 02% higher but 5.07% and 38. 93% lower than that under continuous flooding irrigation, respectively. The water use efficiency was the highest under intermittent irrigation, relatively high under semi-dry cultivation, but relatively low under continuous flooding irrigation and dry cultivation. Compared with other irrigation modes, intermittent irrigation increased the milled rice rate, head rice rate and grain length, while decreased the chalky rice and chalkiness. With the reduction of water consumption, the amylose content of rice grain decreased, but the gel consistency and protein content increased. Intermittent irrigation could be a favorable irrigation mode for the paddy rice planting in Southern China.