不同氮肥水平下优质高产软米粳稻的产量与品质差异

【目的】明确优质高产软米粳稻的产量和品质对氮肥的响应特征。【方法】在前期品种筛选的基础上,选择2个优质食味高产型软米品种为研究对象,设置60 kg/hm²(N1)、120 kg/hm²(N2)、180 kg/hm²(N3)、240 kg/hm²(N4)、300 kg/hm²(N5)与360 kg/hm²(N6) 6个氮肥(以纯氮计)水平,对其产量性状和品质指标进行了测定与分析。【结果】依赖于单位面积穗数、每穗粒数和群体颖花量的协同增加,软米产量在N5下最高,但与N4间无显著差异。随施氮量增加,米粒的外观、黏度、平衡度和食味值呈先增后减,而硬度则先减后增,并在N4或N5下出现峰值;出糙率、出精率和整精米率均随施氮量增加而提高,但垩白米率和垩白度呈先降后增,并在N5水平下最低。随施氮量的增加,直链淀粉含量和胶稠度下降,蛋白质含量升高。米粉峰值黏度、热浆黏度、崩解值和最终黏度随施氮量的增加呈先增后减,在N4或N5下最高。【结论】因此,优质食味软米在240 kg/hm²和300 kg/hm²条件下取得产量和品质的协调,240 kg/hm²是品质、产量和效益兼顾的最佳施氮量。

Differences in Yield and Rice Quality of Soft japonica Rice with High Quality and High Yield Under Different Nitrogen Levels

【Objective】It is very crucial to clarify the response of high quality and high-yield soft rice to nitrogen fertilizer application.【Method】Two soft japonica varieties with high quality and high-yield based on the early selection of varieties were used as experimental materials to study the effects of nitrogen application on the yield and quality under six nitrogen levels including 60 kg/hm² (N1), 120 kg/hm²(N2), 180 kg/hm²(N3), 240 kg/hm²(N4), 300 kg/hm²(N5) and 360 kg/hm²(N6). 【Result】The yield of soft rice was the highest under 300 kg/hm² depending on the synergistic increase of panicle number per unit area, grain number per panicle and spikelet number, and there was no significant difference between N5 and N6. With the increase of nitrogen application, appearance, viscosity, balance and taste value of rice increased firstly and then decreased, hardness decreased and then increased with peak at N4 or N5. The brown rice rate, milled rice rate and head rice rate increased with the increase of nitrogen fertilizer, but the chalky rice rate and chalkiness degree both increased first and then decreased, and both were the lowest at N5. With the increase of nitrogen application, the amylose content and gel consistency both decreased but the protein content increased. The peak viscosity, hot paste viscosity, breakdown and final viscosity of rice flour increased firstly and then decreased, with the highest values at N4 or N5. 【Conclusion】In summary, soft japonica rice with high quality and high yield achieved the coordination of yield and quality under N4 and N5, and N4 was the best nitrogen application taking account of quality, yield and benefit.