氮密互作对信优糯721群体质量及产量构建的影响

Effects of Nitrogen-Density Interaction on the Population Quality and Yield Formation of the Rice Cultivar'Xinyounuo 721'

为探明氮密互作对信优糯721群体质量、产量形成及稻米加工品质的影响,试验利用该品种设置4个氮肥处理水平,分别是A0(对照)、A1施氮180 kg/hm^(2)、A2施氮240 kg/hm^(2)、A3施氮300 kg/hm^(2),设置3个移栽密度梯度,分别为B1,21.5万穴/hm^(2)、B2,25.7万穴/hm^(2)、B3,29.9万丛/hm^(2)。结果表明:干物质积累量方面,同一氮素水平,随着移栽密度的增加呈现增加的趋势;同一移栽密度处理上,拔节期随着氮肥用量的增加干物质积累呈现增加的趋势,SPAD值方面,各处理最大值均在始穗期;产量与氮肥施用量呈正相关,在一定的氮素水平下,有效穗均随着密度的增加呈现增加的趋势;结实率、千粒重随着密度的增加呈现降低的趋势;出糙率、精米率和整精米率最大值均在A2B2处理且精米率和整精率与其他处理表现出显著差异,米粒长宽比受不同氮肥用量和移栽密度影响较小。综上:采用施氮量为240 kg/hm^(2)、密度为25.7万穴/hm^(2)处理,在产量构成因子方面表现较好,且稻米加工品质较优,生产上应以此氮密处理指导生产。

This study aims to reveal the effects of nitrogen-density interaction on the population quality,yield formation,and processing quality of the rice cultivar'Xinyounuo 721'.Four nitrogen application levels were designed,which were A0(CK),A1(180 kg/hm^(2)),A2(240 kg/hm^(2)),and A3(300 kg/hm^(2)).Three transplanting density gradients were designed as B1(215 thousand hills/hm^(2)),B2(257 thousand hills/hm^(2)),and B3(299 thousand hills/hm^(2)).The results showed that the dry matter accumulation of the same nitrogen level increased with the increase in transplanting density.In the case of the same planting density,dry matter accumulation increased with the increase in the nitrogen application level at the jointing stage,and the SPAD value peaked at the early heading stage.There was a positive correlation between the yield and the nitrogen application level.At a certain nitrogen application level,effective panicles increased while the seed setting rate and 1000-grain weight decreased with the increase in planting density.The maximum husked rice yield,milled rice rate,and head rice rate all appeared in the A2B2 treatment,and the milled rice rate and head rice rate in this treatment were significantly different from those in other treatments.The length-to-width ratio of rice grain was slightly affected by the nitrogen application level and planting density.In conclusion,the treatment with nitrogen application at 240 kg/hm^(2)and planting density of 257 thousand hills/hm^(2)had high yield components and rice processing quality.The production should take nitrogen application and planting density into consideration.