不同灌水处理对冬小麦生长及水分利用效率的影响

1998～ 1 999年在山东省桓台县进行了冬小麦节水灌溉试验。通过对冬小麦生长动态观测表明 :减少灌水量可以促进冬小麦发育。起身拔节水对冬小麦株高有显著影响。叶面积指数、冠层干物重、根系总量随着灌水量的增加而增加。各处理冬小麦根系总量的 80 %以上分布在 0～ 2 0 cm土层内。随着灌水次数的增加 ,灌水量的增多 ,灌溉水的利用效率逐渐减小。全生育期浇越冬水、起身拔节水、开花水的处理经济产量最高 ,达到 771 6.7kg/hm2 ,水分利用效率最大 ,达到 1 5 .92 kg/(hm2· mm) ,单位水资源量的边际效率也最大 ,达43 .1 2 kg/mm,单次灌水的最大平均产量为 85 1 .65 kg/hm2。

Effects of Irrigation Scheduling on Development and Water Use Efficiency in Winter Wheat

An irrigation experiment was conducted in winter wheat in Huantai county, Shandong province in 1998～1999 growing season. Development data showed that growth process of winter wheat may be promoted by reducing irrigation quota. Plant height was affected notably by irrigation in jointing stage. Leaf area index, dry matter amount above ground, and root capacity increased with irrigation quota increasing. Over 80% of roots distributed in soil layer of 0～20 cm. Water use efficiency decreased gradually with irrigation times and quota increasing. The highest yield of 7716.7 kg/hm 2, water use efficiency of 15.92 kg/(hm 2·mm), margin efficiency of 43.12 kg/mm and average yield increment per irrigation of 851.65 kg/hm 2 all was achieved in irrigation treatment with three irrigations: before over winter, jointing, and flowering.