豫北引黄灌区水稻控制灌溉节水技术试验

Experimental Study on Rice Water-Saving Technique by Controlling Irrigation Carried out at the Yellow River Diversion Irrigation Area in Northern Henan Province

以土壤饱和含水率为上限，以50％、60％、70％饱和含水率为控灌下限，对水稻全生育期生理生态变化及产量结构与常规灌（即淹水灌溉）进行了对比试验。结果表明：50％、60％两种控灌处理，水分利用效率较常规灌高，但产量相对较低；4种处理中只有70％控灌的产量最高，水分利用效率也最高，与常规灌相比增产2．6％、耗水量减少41．4％，效益十分显著，是节水高效的灌溉方式。在管理方面，水稻控制灌溉必须在水稻完全返青，即叶片顶部没有黄尖现象后方可实施，否则对水稻的茎蘖数有明显不利影响。水稻控制灌溉灌水时间除可实时监测预报外，还可根据灌水间隔或地表特征简易掌握，在没有降雨的情况下，70％控灌一般间隔4—6d灌水一次。

A series of control irrigation tests on rice with control indicator of up-layer （0 -40cm） soil moisture content at 50%, 60%, and 70% （ SMC ） respectively together with flush irrigation were carried out and the contrast testing results show that the irrigation efficiencies of control irri- gation at water content of 50% and 60% （SMC） are higher than that of the flush irrigation but the grain yields are lower. However, both irrigation efficiency and grain yield reach the peak when the control proportion is set as 70% （ SMC）, and also the multifold benefits such as grain production increase, water saving and irrigation management works decrease can be achieved at the same time. The control irrigation can only be practiced after the transplanted seedling turn green completely, i.e. the yellow color at the end of the lamina fades away and the seedling begin reviving, in case the growth of the crop may suffer seriously. The time to carry out the control irrigation can be predicted according to the field monitoring results as well as the interval of irrigation and characters of the soil. Generally speaking, the rice needs one control irrigation （when MC of the up-layer soil reaches 70% SMC） every 4 to 6 days if no rain water is available, and the exact interval depends on the temperature level.