不同生态条件下施氮量和移栽密度对杂交稻旌优127产量及稻米品质的影响

为明确不同生态条件下施氮量和移栽密度对杂交稻产量形成和稻米品质的影响,以旌优127为试验材料,研究了2种施氮量(中等施氮量MN,120 kg·hm-2;高等施氮量HN,180 kg·hm-2)和3个移栽密度(12.0、16.5、22.5穴·m-2,记作D1、D2、D3)下,德阳、泸州生态点杂交稻产量、产量构成、干物质生产、稻米品质的变化。结果表明,德阳点土壤全氮、碱解氮含量高于泸州点,德阳点播种至齐穗平均太阳辐射、最高温度、最低温度均高于泸州点,但其齐穗至成熟平均太阳辐射、最高温度、最低温度低于泸州点。与泸州点相比,德阳点杂交稻产量、糙米率和精米率分别增加了14.3%~24.3%、0.9%~1.9%和0.7%~5.3%,其增产优势主要表现在有效穗、每穗粒数、生物产量和收获指数上。不同生态条件下施氮量和移栽密度对杂交稻产量形成和稻米品质的影响不同。德阳点杂交稻产量随施氮量增加而减少,相同施氮量水平下杂交稻产量随移栽密度的增加而增加,以MND3产量最高,为10.87~11.72 t·hm-2,且该密肥组合下碾米的品质、外观、食味相对较好。泸州点杂交稻产量随施氮量和移栽密度的增加而增加,以HND3产量最高,达到9.25~9.85 t·hm-2,碾米的品质、食味相对较好。德阳点的最佳密肥组合为120 kg·hm-2和22.5穴·m-2;泸州点的密肥组合为180 kg·hm-2和22.5穴·m-2。由此可见,合理的施氮量和适宜的移栽密度有助于提高杂交稻产量和稻米品质。本研究结果为不同生态稻区肥料优化管理和合理密植提供了理论依据。

Effects of Nitrogen Fertilization and Planting Density on Grain Yield and Quality of Jingyou127 and Rice Quality Under Different Ecological Conditions

The objective of this study was to explore effect of nitrogen (N) applied rate and planting density on yield formation and rice quality of hybrid rice under different ecological conditions.Hybrid rice,Jingyou127,was grown under two N rates (medium nitrogen rate,MN,120 kg· hm-2;high nitrogen rate,HN,180 kg· hm-2 and three planting densities (12.0 hills· m-2,D1;16.5 hills· m-2,D2;22.5 hills· m-2,D3) in Deyang and Luzhou in Sichuan Province.Grain yield,yield components,biomass production and rice quality were measured for each treatment in each location.The result showed that the soil total N and available N contents in Deyang were higher than that in Luzhou.The mean solar radiation,maximum and minimum temperature from sowing (SO) to heading (HD) in Deyang were higher than that in Luzhou,while the mean solar radiation,maximum and minimum temperature from HD to maturity (MA) in Deyang were lower than that in Luzhou.The yield,brown rice percentage and milled rice percentage of the rice in Deyang were 14.3％ to 24.3％,0.9％ to 1.9％ and 0.7％ to 5.3％ higher than that in Luzhou,which was mainly due to the contribution of higher panicle number,spikelets per panicle,biomass and harvest index.In Deyang,rice yield decreased with N rate increasing,and increased with planted density increasing,the highest grain yield (10.87 to 11.72 t·ha-1) was recorded in the combination of medium nitrogen rate with high planted density.Similarly,hybrid rice had relatively high milling efficiency,appearance and cooking and eating characteristics under the combination of medium nitrogen rate with high planted density.In Luzhou,rice yield increased with nitrogen rate and planted density increasing.Under the combination of high nitrogen rate with high planted density,hybrid rice produced the highest grain yield (9.25 to 9.85 t· ha-1),and had relatively high milling efficiency and cooking and eating characteristics.Our results indicated that grain yield and rice quality of hybrid rice could be simultaneously improved by the optimal combination of N rate and planting density,but which varied with rice production region.For rice production in Deyang,the optimum combination is N 120 kg·ha-1 plus density of 22.5 hills·m-2,and N 180 kg·ha-1 plus density of 22.5 hills· m-2 in Luzhou.This study provides a theoretical basis for the optimum fertilizer management and planted density in different rice production region.