不同灌溉方式对水稻生物学特性的影响

Impact of different irrigation methods on biological characteristics of rice

为充分发挥水稻的产量潜力和实现水分高效利用，以超级杂交水稻“两优培九”和“红莲优6号”为材料，比较了间歇灌溉（B）、半旱栽培（C）、干旱栽培（D）和淹水灌溉（A）方式下的水稻生物学特性。结果表明：随着田间灌水量的减少，水稻生育期延迟，生育期最长的干旱处理与淹水处理的全生育期天数相差长达13．5d。间歇灌溉水稻的最高分蘖期比淹水灌溉推迟5～7d。与淹水灌溉相比，间歇灌溉的叶片光合速率高，叶面积指数大，叶片蒸腾速率较低，提高了水分利用率；半干旱栽培的水稻叶片蒸腾速率比净光合速率下降快，水分利用率相对较高；干旱栽培的叶片净光合速率降低，水分利用率低，后期叶片出现早衰。间歇灌溉与淹水灌溉的水稻株高、叶面积指数、气孔导度差异不显著，但与半旱和干旱栽培差异显著。综上所述，间隙灌溉比其他3种灌溉方式能更好地改善水稻生物学特性，在生产上有较好的利用前景。

The biological characteristics of super-hybrid rice cuhivars ＂Liangyoupeijiu＂ and ＂Honglianyou No. 6＂ were compared to evaluate rice production potential and water use efficiency under 4 different irrigation methods, including intermittent irrigation （B） , semi-dry cultivation （C） , dry cultivation （D） and continuous flooding （A）. The results show a delay in rice growth with decreasing irrigation trend. Growth duration under dry cultivation is the longest and lags by 13.5 days, compared with continuous flooding. Tillering occurs 5 to 7 days later under intermittent irrigation than under continuous flooding. Compared with continuous flooding, intermittent irrigation improves leaf photosynthetic rate, decreases leaf transpiration rate and increases leaf area index, thus water use efficiency of rice. Leaf transpiration rate declines more rapidly than pure photosynthetic rate, thus water use efficiency is relatively higher under semi-dry cultivation. Both pure photosynthetic rate and water use efficiency are much lower, and leaf presenility occurs under dry cultivation in the late growth stage. Significant differences in plant height, leaf area index and stomatal conductance are observed between intermittent irrigation and semi-dry, dry cultivations, but not between intermittent irrigation and continuous flooding. Thus intermittent irrigation method improves rice biological characteristics the most when compared with the other 3 irrigation methods and therefore preferred recommended practice.