【作者】 何虎；

【导师】 潘晓华；

【作者基本信息】 江西农业大学 ， 作物栽培学与耕作学， 2011， 硕士

【摘要】 于2009年和2010年,以淦鑫688为材料探讨了稻草全量还田下氮肥运筹对其产量和稻米品质的影响。主要结果如下：1、稻草还田对产量及其构成的影响与稻草不还田相比,稻草全量还田下有效穗数、结实率和千粒重均增加,每穗粒数下降,晚稻产量提高；成穗率、生物产量和氮肥当季利用率提高,后期根系和叶片衰老慢；稻米外观、蒸煮和食味品质得到改善。2、稻草还田下氮肥运筹对晚稻产量、产量构成及稻米品质的影响(1)施氮量与产量呈抛物线关系,产量在施氮180kg/hm2最高；在施氮量均等时,以基肥：分蘖肥：穗肥=5：2：3产量最高。随着施氮量增加,分蘖成穗率下降。一次枝梗分化数和倒一节间大维管束数均以施氮180kg/hm2处理最多；粒束比以基肥：分蘖肥：穗肥=5：2：3最低。(2)施氮越多,生物产量和叶面积指数越高,而茎鞘物质输出率、转换率和贡献率均以施氮180kg/hm2最高；等量施氮下,基蘖肥越多,生物产量越高,茎鞘物质输出率和转换率以基肥：分蘖肥：穗肥=5：2：3处理最高。(3)随着施氮量增加,氮素积累和表观利用率提高,百公斤籽粒需氮量增加,施氮180kg/hm2时氮肥农艺利用率最高。等量施氮下,氮肥农艺、生理利用率均以基肥：分蘖肥：穗肥=5：2：3最高。(4)株高、顶三叶叶长均随施氮量增加而增加,剑叶、倒三叶弯曲角以施氮180kg/hm2处理最高。施氮量越多,根系活力衰退越慢,颖花伤流量、气叶温差和冠层叶片SPAD值和净光合速率越高；等量施氮下,以基肥：分蘖肥：穗肥=5：2：3的根系活力衰退值最小,该处理齐穗期剑叶净光合速率也最高。(5)增加施氮量可以降低土壤耕层温度；相同施氮量下,5cm和10cm耕层处的温度以基肥：分蘖肥：穗肥=5：2：3处理最高。(6)稻草还田后增加施氮量,出糙率提高,垩白度下降；等量施氮下,穗肥施用越多,出糙率、精米率越高。更多还原

【Abstract】 In order to investigate the effects of nitrogen application under the full amount straw returning on grain yield and quality of late rice, used the late season rice GanXin 688 as materials, the experiments were carried out during 2009 and 2010. The main results were as follows:1、Effects of straw returning on grain yield and its components:Compared with control(no straw returning), the full amount of straw returning increased effective panicles, filled grain rate and 1000-grain weight, but reduced grain number per panicle and promoted rice yield. Straw returning enhanced the percentage of productive tiller and the biomass and the utilization of nitrogen,and delayed the leaf senescence after heading.The rice appearance, cooking and eating quality are improved.2、Effects of the nitrogen application on grain yield and its components as well as the rice quality after straw returning:(1)A parabola relationship was found between the nitrogen application rate and the grain yield and with nitrogen 180 kg/hm2, the yield was highest. With same nitrogen application rate(180kg/hm2), the yield is highest under the ratio of basal nitrogen:tiller nitrogen:panicle nitrogen was 5:2:3.With the nitrogen application rate increased, the percentage of productive tiller was declined. The number of primary branch differentiation and large vascular bundles in the uppermost internode are both most nuder nitrogen 180 kg/hm2. The ratio of grain number to large vascular bundle is lowest when basal nitrogen:tiller nitrogen:panicle nitrogen was 5:2:3.(2) The more nitrogen application, the higher biomass and LAI.The translocation of dry matter in stem and sheath and its contribution rate to yield were highest under the nitrogen application level was 180kg/hm2. With same nitrogen application rate, the more nitrogen application level, the higher biomass. The translocation of dry matter in stem and sheath and its contribution rate to yield were highest under basal nitrogen:tiller nitrogen:panicle nitrogen was 5:2:3.(3) When nitrogen application increasing, the total N accumulation,the N using efficiency and the needed nitrogen for produced 100 kg of grain.The N agronomic efficiency was highest under the nitrogen application level was 180kg/hm2. With same nitrogen application rate, the N agronomic efficiency and N physiological efficiency were highest under basal nitrogen:tiller nitrogen:panicle nitrogen was 5:2:3.(4) The more nitrogen application, the higher the plant height and the top three leaves.The flag leaf and bend angle of pour trilobites were largest under the nitrogen application level is 180kg/hm2. An higher spikelets-bleeding-intensity temperature depression(difference between air temperature and flag leaf temperature), flag leaf SPAD and net photosynthetic rate, and smaller the degradation rate of root acticity after heading were found as nitrogen application increased. With same nitrogen application rate, the degradation rate of root acticity were lowest under basal nitrogen:tiller nitrogen: panicle nitrogen was 5:2:3. Net photosynthetic rate of the flag leaf in full-heading stage was highest under the nitrogen application level was 180kg/hm2 and basal nitrogen: tiller nitrogen:panicle nitrogen was5:2:3.(5) When nitrogen application level increasing, the soil temperature reduced. With same nitrogen application rate, the soil temperature in 5cm and 10cm were highest under basal nitrogen:tiller nitrogen:panicle nitrogen was 5:2:3.(6) As nitrogen application increased, the rate of husked was rised and the percentage of grains with Chalkiness was lower. With same nitrogen application rate, the more panicle nitrogen, the higher the rate of husked and milled rice.更多还原