一、引言灌溉供水与水稻生长发育的关系极为密切,常成为水稻水分生理与水稻生产的重要环节。我国北方稻区由于水资源不足,加上工业和城市用水量的日益增大,工业和城市用水与农业用水的矛盾十分突出。现在,某些地区水稻生产由原来的水层灌溉逐渐被节水灌溉或旱种栽培所代替,稻作正由水层栽培的生态体系向无水层的旱作栽培体系转 I. INTRODUCTION The relationship between irrigation water supply and rice growth and development is extremely close and often becomes an important part of rice water physiology and rice production. Due to the shortage of water resources and the increasing industrial and urban water consumption in the northern part of China, the contradiction between industrial and urban water use and agricultural water use is very conspicuous. Now, in some areas, rice production has been gradually replaced by water-saving irrigation or dry-farming cultivation from the original water-level irrigation system. Rice is being transformed from a water-layer ecosystem into a dry-layer cultivation system with no water layer