摘要
为了探明增苗节氮技术高产群体的适宜群体指标,在大田裂区试验下比较了3个氮肥水平[N1:105 kg/hm2(节氮)、N2:135 kg/hm2(节氮)、N3:165 kg/hm2(常氮)]和3个抛秧密度[M1:27万穴/hm2(常苗)、M2:31.5万穴/hm2(增苗)、M3:36万穴/hm2(增苗)]对‘湘早籼45号’抛秧群体质量及光合参数的影响。结果表明:在不影响产量的前提下,氮肥用量能比当前习惯施氮量减少18.2%,但进一步降低施氮量(减少36.4%)存在减产风险;氮肥、密度对作物生长率、净同化率、叶面积指数、叶面积衰减率、叶面积比率、表观转运率、光合势、粒叶比等群体指标均有一定影响,产量最高组合(N2M3)各项指标值位于中间范围内;N2M3的净光合速率、气孔导度、蒸腾速率、水分利用率也处于适中水平。综上所述:"增苗节氮"下早稻抛秧高产群体各项群体指标应该在适中范围内,实行合理搭配,以构建适宜群体来实现高产,而不是为了追求高产而盲目地增加氮肥用量,从而减少过度施用氮肥对生态环境所带来的危害。
The Population quality and photosynthetic parameters of rice ＇Xiangzhaoxian 45＇ of throwing transplanting under three nitrogen levels [N1：105 kg/hm2 （low nitrogen dose）; N2：135 kg/hm2 （low nitrogen dose）; N3：165 kg/hm2 （regular nitrogen dose）] combined with 3 seedling densities [MI： 0.27 million hills per hectare （regular seedling rate）; ME： 0.315 million hills per hectare （high seedling rate）; M3：0.36 million hills per hectare （high seedling rate）] in a split-plot trial field were compared to verify suitable population index of high-yielding groups under seedlings-increase and nitrogen-reduction measures. The results showed that： under the premise of not affecting production, nitrogen fertilizer could reduce 18.2% when compared with current habitual amount, but the risk of reducing production would arise when nitrogen fertilizer reduced further （reduce 36.4%）. Nitrogen and density had certain influence on population index of crop growth rate, net assimilation rate, leaf area index, leaf area decay rate, leaf area ratio, export rate, photosynthetic potential and grain leaf ratio etc., each population index value of N2M3 was in the moderate range; net photosynthetic rate, stomatal conductance, transpiration rate and water use efficiency of the highest yield combination （N2M3） were also at a moderate level. In summary, the population index value of high-yielding groups of early rice by throwing transplanting ought to be moderate level under seedling-increase and nitrogen-reduction measures, building suitable groups could reach high yield through reasonable collocation between nitrogen fertilizer and density, rather than increased nitrogen fertilizer blindly to pursue high-yielding, thus reduced the harm to environment on account of excessive nitrogen fertilizer application.
出处
《中国农学通报》
CSCD
2014年第27期5-14,共10页
Chinese Agricultural Science Bulletin
基金
"十二五"国家科技支撑计划重大项目"长江中游南部(湖南)水稻丰产节水节肥技术集成与示范"(2013BAD07B11)
湖南省科技重大专项"稻米镉污染消减及快速检测技术与装备研究"(2011FJ1002)
关键词
增苗节氮
早稻
抛秧
群体质量
群体指标
光合参数
seedling-increase and nitrogen-reduction
early rice
seedling throwing
population quality
population index
photosynthetic parameters
