施氮量对江汉平原优质稻产量和品质的影响

Effect of Nitrogen Application Rate on Yield and Quality of High-Quality Rice in Jianghan Plain

选用6个典型长粒形优质籼稻品种(鄂中5号、鉴真2号、泰优鄂香丝苗、桃优香占、象牙香占、野香优莉丝),研究不同施氮量[105 kg/hm^(2)(N1)、135 kg/hm^(2)(N2)、165 kg/hm^(2)(N3)、195 kg/hm^(2)(N4)和225kg/hm^(2)(N5)]下6个优质稻品种产量及其构成因素和加工、外观、蒸煮、营养品质的变化,探讨优质稻高产、优质的合理施氮量,为优质稻的高产栽培技术推广提供理论依据。结果表明,水稻产量随着施氮量的增加呈先增加后降低的趋势,总体上以N2和N3处理产量较高,两者差异不显著。其中,鄂中5号、泰优鄂香丝苗、桃优香占均以N3处理产量最高,分别为7.4、10.3、10.0 t/hm^(2);鉴真2号、象牙香占、野香优莉均以N2处理最高,分别为9.0、8.3、10.3 t/hm^(2)。产量提高主要得益于有效穗数和结实率提高。6个品种间产量表现为桃优香占>泰优鄂香丝苗>野香优莉丝>鉴真2号>象牙香占>鄂中5号。在品质方面,除野香优莉丝外,其余各品种的稻谷加工品质对施氮量的反应比较一致,糙米率、精米率、整精米率总体上均以N2和N3处理较高;垩白粒率和垩白度表现为鉴真2号、泰优鄂香丝苗、象牙香占均以N3处理最低,桃优香占和野香优莉丝均以N2处理最低。各优质稻品种间垩白粒率和垩白度表现为泰优鄂香丝苗>鉴真2号>桃优香占>象牙香占、野香优莉丝>鄂中5号。对于直链淀粉含量,野香优莉丝以N2处理最低,象牙香占以N4处理最低,其余4个品种均以N3处理最低;对于淀粉RVA谱特征值,鄂中5号、泰优鄂香丝苗均以N3处理崩解值最高、消减值最低,鉴真2号、桃优香占和象牙香占均以N1处理崩解值最高、消减值最低,野香优莉丝以N2处理崩解值最高、消减值最低。对于精米粗蛋白含量及其组分含量,鄂中5号和桃优香占粗蛋白含量较低,为4.5%~5.9%;其余4个品种粗蛋白含量较高,介于10.4%~15.4%。大部分品种清蛋白含量以N5处理最高;大部分品种醇溶蛋白含量以N4处理最高;球蛋白和谷蛋白含量随施氮量的增加先上升后下降,大部分品种以N3处理最高。综合来看,江汉平原地区适宜优质稻生产的优化施氮量为135~165 kg/hm^(2)。

Six typical long-grain high-quality indica rice varieties(Ezhong 5,Jianzhen 2,Taiyouexiangsimiao,Taoyouxiangzhan,Xiangyaxiangzhan,Yexiangyoulisi)were selected to study the yield and its component and processing,appearance,cooking,nutritional qualities under different nitrogen application rates[105kg/ha(N1),135 kg/ha(N2),165 kg/ha(N3),195 kg/ha(N4)and 225 kg/ha(N5)],and the reasonable nitrogen application rate for high yield and quality of rice was explored,so as to provide a theoretical basis for the promotion of high-yield cultivation technology of high-quality rice.The results showed that the yield of rice increased first and then decreased with the increase of nitrogen application rate,the yields of N2 and N3 were generally higher,and there was no significant difference between them.Ezhong5,Taiyouexiangsimiao and Taoyouxiangzhan had the highest yield under N3 treatment,which were 7.4,10.3,10.0 t/ha;Jianzhen 2,Xiangyaxiangzhan and Yexiangyoulisi had the highest yield under N2treatment,which were 9.0,8.3,10.3 t/ha.The main reason for the increase of yield was the increase in the effective panicle number and seed setting rate.The yield order was Taoyouxiangzhan>Taiyouexiangsimiao>Yexiangyoulisi>Jianzhen 2>Xiangyaxiangzhan>Ezhong 5.In terms of quality,except for Yexiangyoulisi,the rice processing quality of the remaining varieties had a consistent response to the nitrogen application rate.N2 and N3 treatments generally had higher brown rice rate,polished rice rate and whole polished rice rate;for chalkiness degree and chalkiness rate,Jianzhen 2,Taiyouexiangsimiao and Xiangyaxiangzhan were the lowest under N3 treatment,Taoyouxiangzhan and Yexiangyoulisi were the lowest under N2 treatment.The order of chalkiness degree and chalkiness rate was Taiyouexiangsimiao>Jianzhen 2>Taoyouxiangzhan>Xiangyaxiangzhan and Yexiangyoulisi>Ezhong 5.For the amylose content,Yexiangyoulisi had the lowest value under N2 treatment,Xiangyaxiangzhan had the lowest value under N4 treatment,the other four varieties had the lowest value under N3 treatment.In terms of the characteristics of starch RVA spectrum,Ezhong 5 and Taiyouexiangsimiao had the highest breakdown viscosity and lowest setback value under N3 treatment,Jianzhen 2,Taoyouxiangzhan and Xiangyaxiangzhan had the highest breakdown viscosity and lowest setback value under N1 treatment,and Yexiangyoulisi had the highest breakdown viscosity and lowest setback value under N2 treatment.In terms of the crude protein content and its components contents of polished rice,Ezhong 5 and Taoyouxiangzhan had lower crude protein content of 4.5%—5.9%,the other four varieties had higher crude protein content of 10.4%—15.4%.The albumin content of most varieties was the highest under N5 treatment;the gliadin content of most varieties was the highest under N4 treatment;the contents of globulin and gluten increased first and then decreased with the increase of nitrogen application rate,and N3 treatment was the highest for most varieties.On the whole,the optimal nitrogen application rate suitable for high-quality rice production was 135—165 kg/ha in the Jianghan Plain area.