施氮量对超级杂交稻产量和稻米品质的影响

为探明超级杂交稻在成都平原的适宜施氮量,达到高产与优质协同,以超级杂交稻德优4727、普通杂交稻川优6203和常规稻五山丝苗为材料,于2016年在四川德阳进行大田试验,设置4个施氮量(0、120、165、210 kg/hm~2,分别记作N0、N120、N165、N210),研究施氮量对水稻产量和稻米品质的影响。结果表明,超级杂交稻产量随施氮量的增加呈先增加后下降的趋势,以N165处理最高;普通杂交稻和常规稻产量随施氮量的增加而增加,以N210处理最高,但与N165处理差异不显著。糙米率、整精米率、蛋白质含量随施氮量的增加而提高;垩白粒率、垩白度对氮肥的响应因品种而异。除普通杂交稻胶稠度外,施氮量对胶稠度和直链淀粉含量的影响不显著。品种间产量和品质均存在显著差异。与普通杂交稻和常规稻相比,超级杂交稻产量显著增加,增产优势主要表现在粒重上。超级杂交稻糙米率、垩白粒率、垩白度、胶稠度显著高于常规稻,直链淀粉含量和蛋白质含量低于常规稻;超级杂交稻整精米率显著高于普通杂交稻,但与常规稻相当。考虑产量和品质两因素,本试验条件下超级杂交稻选择纯N用量165 kg/hm~2,可实现产量和品质的协同提高。

Effects of Nitrogen Application Rate on Yield and Grain Quality of Super Hybrid Rice

A field experiment was conducted to study the effects of nitrogen application rate on yield and grain quality of super hybrid rice Deyou4727, ordinary hybrid rice Chuanyou 6203 and conventional rice Wushansimiao in Deyang City, Sichuan Province in 2016. The three cultivars were grown under four N treatments (0, 120, 165 and 210 kg/hm2 N, named N0, N120, N165 and N210). The results showed that the yield of super hybrid rice was increased with the increasing of N application rate at first and then decreased; the treatment N165 produced the maximum yield. The yields of ordinary hybrid and conventional rice were increased with the nitrogen ap-plication rate increasing, the treatment N210 recorded the maximum yield, and had no significant difference with treatment N165. The brown rice rate, head rice rate and protein content were increased with the nitrogen application rate increasing. The chalky rice rate and chalkiness degree response to nitrogen application rate varied with cultivars. Nitrogen application rate had no significant effects on gel consistency and amylase content except for gel consistency of ordinary hybrid rice. The difference in yield and grain quality among the cultivars were significant. The yield of super hybrid rice was increased by 8.0％ compared with ordinary hybrid rice and conven-tional rice. The higher yield is due to higher grain weight. The brown rice rate, chalky rice rate, chalkiness degree and gel consistency of super hybrid rice were significantly higher than those of conventional rice, but had lower amylase content and protein content. The head rice rate of super hybrid rice was significantly higher than that of ordinary hybrid rice, but slightly lower than that of convention-al rice. Considering the yield and grain quality, the optimum nitrogen application rate of 165 kg/hm 2 was proposed for super hybrid rice Deyou 4727 in Chengdu Plain.