水稻不同需水关键期适宜灌水下限指标研究

在5 m2有底测坑内研究水稻拔节孕穗期和抽穗开花期70%～90%土壤饱和含水率灌水下限对灌溉制度、渗漏量和产量等的影响。结果表明,不同灌水条件下,灌水次数、灌水模数、灌溉定额发生较大变化,灌水次数在本田期为28～37次,灌溉定额为8 190～9 450 m3/hm2,各处理渗漏量随着灌水量的降低而降低,渗漏量为灌水量的54.22%～64.25%,拔节孕穗期较抽穗开花期需水更敏感,拔节孕穗期应保持湿润状态,抽穗开花期适宜灌水下限为90%。

The Lowest Optimal Irrigation Bound on the Different Key Water Requirement Period of Rice

This paper studies on the influence of the irrigation schedule,leakage and yield of the jointing-booting stage and the full heading stage under the condition of continuous irrigation with 70 to 90 percent saturated soil moisture content in the 5 m2 test-pits.The results showed that the irrigation times,modulus and quota changed in the different irrigation conditions.The irrigation times were from 28 to 30,the irrigation quota was 8 190 to 9 450 m3/hm2,during rice growth period.The leakage of different treatment decreased with the irrigation quantity decreasing.The leakage was from 54.22 to 64.25 percent of the irrigation quality.The irrigation requirement of the jointing-booting stage was more sensitive than the full heading stage.The jointing-booting stage should keep wetness state and the lowest optimal irrigation bound of the full heading stage was 90 percent.