分蘖和乳熟期控制灌溉对水稻生长和产量的影响

为了合理的制定水稻控灌灌溉制度,开展了单生育期内水分控制灌溉对水稻生长影响的试验研究。在水稻分蘖（FN）和乳熟期（RS）分别以土壤饱和含水量的80%（FN1,RS1）和90%（FN2,RS2）作为灌溉下限进行控制灌溉。结果表明：与常规浅湿灌溉相比,生育期水分控制灌溉可以减少该生育期内灌水次数和灌水量,控制灌溉停止后,分蘖期处理水稻需水出现补偿效应,乳熟期则不明显;控制灌溉不利于水稻株高生长,有利于增加每穗粒数和每穗实粒数,对千粒重影响不明显;控制灌溉节水效应显著,但同时减产作用也十分明显,FN1、FN2、RS1和RS2处理分别节水21.1%,16.2%,29.4%和18.1%,减产27.8%,26.8%,29.5%和19.2%;分蘖期控制灌溉减产作用大于节水作用,灌溉水利用效率（IWUE）显著下降,较对照处理降低8.5%～12.7%,乳熟期控制灌溉IWUE和对照差异不显著。因此,从生产角度来讲,当灌溉水水资源匮乏需要控制灌溉时,为了提高IWUE,宜在乳熟期适当控灌,而分蘖期不宜控制灌溉。

Effects of Controlled Irrigation on Rice Growth and Yield in Tillering and Milk Stage

In order to apply the controlled irrigation technique for rice planting more reasonably, the effect of controlled irrigation in a single growing stage on rice growth and yield was studied. Water control was launched in tillering （FN） and milk stage （RS） respectively, and in each stage, soil water content 180% （FN1, RS1）, and 90% （FN2, RS2）, respectively] was controlled. The results showed that, compared to check treatment, water control decreased irrigation times and amount; compensatory effect appeared as controlled irrigation implemented in tillering stage while it was unobvious implemented in milk stage. Controlled irrigation was against rice growth but conductive to the number and effective number of grain per ear, while it had little effect on thousand seed weight. Though controlled irrigation saved irrigation water apparently, it decreased yield obviously, FN1, FN2, RS1 and RS2 saved irrigation water about 21.1%, 16.2%, 29.4% and 18.1%, while yield decreased 27.8%, 26.8%, 29.5% and 19.2%. Since reduction of output was more than water saving for controlled irrigation during the tillering stage, irrigation water use efficiency （IWUE） of the treatment decreased 8.5%-12.7%, while IWUE little varied as controlled irrigation implemented in milk stage. Therefore, from the production aspect, to get higher IWUE while irrigation water limited, controlled irrigation at milk stage should be concerned, while controlled irrigation at tillering sta~e should be avoided.