【作者】 张娟；

【导师】 贺明荣；

【作者基本信息】 山东农业大学 ， 作物栽培学与耕作学， 2014， 博士

【摘要】 于2011-2013两年度小麦生长季在山东兖州新兖镇杨庄村大田，以冬小麦多穗型品种济麦22和大穗型品种泰农18为供试材料，分别采用裂区设计，设置不同的氮肥水平（0、180和240kg/hm2）和种植密度（济麦22为低密度120万/hm2、中密度180万/hm2和高密度240万/hm2，泰农18为低密度135万/hm2、中密度270万/hm2、高密度405万/hm2）水平，氮肥水平为主因素，种植密度为副因素，结合15N微区试验，研究了种植密度和氮肥水平互作对小麦籽粒产量和氮素利用效率的影响。研究结果如下：1种植密度和氮肥水平对小麦产量形成的影响1.1对小麦干物质积累的影响氮肥水平相同的条件下，随种植密度增加，两品种小麦成熟期干物质积累量显著增加；出苗-冬前、冬前-拔节和开花-成熟的这三个生育阶段干物质积累量显著提高，出苗-冬前、冬前-拔节阶段干物质积累量占成熟期干物质积累量的比例显著提高，拔节-开花阶段干物质积累量占成熟期干物质积累量的比例显著降低；种植密度相同的条件下，随氮肥水平增加，小麦成熟期干物质积累量显著增加；出苗-冬前、冬前-拔节和开花-成熟各生育阶段干物质生产量均显著增加，开花-成熟期干物质积累量占成熟期干物质积累量的比例显著提高。1.2对小麦籽粒产量、生物产量和收获指数的影响种植密度和氮肥水平及其互作效应对两品种籽粒产量的影响均达显著水平。在不施氮和施氮量为180kg/hm2的条件下，生物产量和籽粒产量随种植密度增加而增加，收获指数无显著差异，在施氮量为240kg/hm2的条件下，高密度处理生物产量显著大于中密度处理，收获指数显著低于中密度处理，籽粒产量无显著差异，高密度和中密度处理生物产量和籽粒产量均显著大于低密度处理。施氮量为180kg/hm2的高密度处理籽粒产量与施氮量为240kg/hm2的高密度和中密度处理产量无显著差异。1.3对小麦籽粒灌浆特性的影响在不施氮条件下，随种植密度增加，灌浆速率最大时出现时间、活跃生长期、渐增期、快增期和缓增期均无显著差异，灌浆速率最大时粒重，最大灌浆速率以及平均速率均呈降低的趋势，成熟期粒重降低；在施氮量180kg/hm2条件下，随种植密度增加，除活跃生长期和渐增期无显著差异外，灌浆速率最大时出现时间推迟、快增期和缓增期延长，灌浆速率最大时粒重，最大灌浆速率以及平均速率均呈降低的趋势，成熟期粒重降低；在施氮量240kg/hm2条件下，随种植密度增加，灌浆速率最大时出现时间推迟，活跃生长期、渐增期、快增期和缓增期均延长，灌浆速率最大时粒重，最大灌浆速率以及平均速率均呈降低的趋势，成熟期粒重降低。泰农18的平均籽粒灌浆速率显著低于济麦22。1.4开花后营养器官干物质向籽粒的转运及对籽粒的贡献在不施氮条件下，增加种植密度显著提高花前营养器官干物质贮藏再转运量和花后干物质生产量，花前营养器官贮藏干物质再转运率和对籽粒的贡献率无显著差异；施氮量180kg/hm2条件下，增加种植密度显著提高花前营养器官干物质贮藏再转运量和花后干物质生产量，花前营养器官干物质贮藏再转运率降低；施氮量240kg/hm2条件下，随种植密度增加，花后干物质生产量和对籽粒的贡献率显著增加，花前营养器官干物质贮藏再转运量表现先增加后降低的趋势，花前营养器官干物质贮藏再转运率和对籽粒的贡献率降低。同一种植密度条件下，随氮肥水平增加，花前营养器官干物质贮藏再转运量、转运率以及对籽粒的贡献率降低，花后干物质生产量和对籽粒的贡献率升高。2对小麦氮素吸收效率的影响2.1对小麦氮素积累的影响氮肥水平相同的条件下，随种植密度增加，成熟期地上部氮素积累量增加；增加种植密度显著提高了出苗-冬前、冬前-拔节和开花-成熟的这三个生育阶段氮素积累量和所占吸收氮素的比例；种植密度相同的条件下，随氮肥水平增加，各生育阶段氮素积累量均显著增加，开花-成熟期氮素积累量占总积累量的比例增加。2.2对小麦氮素吸收效率的影响同一氮肥水平条件下，随种植密度增加，小麦氮素吸收效率增加；同一种植密度条件下，随氮肥水平提高，小麦氮素吸收效率降低，种植密度和氮肥水平对小麦氮素吸收效率互作效应达显著水平，表现为高种植密度和低氮肥水平处理氮素吸收效率最高。2.3对小麦不同土层氮素吸收的影响随着标记层次的下移，各处理15N氮素吸收量均降低。氮肥水平相同的条件下，增加种植密度提高了小麦根系对各个土层氮素的吸收，各土层增加的氮素吸收量和比例随标记层次的下移而显著提高；种植密度相同的条件下，增施氮肥增加了小麦根系对20cm和60cm处土层氮素的吸收，降低了100cm土层氮素的吸收量。氮素吸收量与20cm和60cm的氮素吸收量呈显著正相关关系，氮素吸收效率与100cm的氮素吸收量呈显著正相关关系，表明可以通过调节种植密度和氮肥水平改变小麦根群结构以及在各个土层的分布，同步提高小麦氮素吸收量和氮素吸收效率。3对小麦氮素利用效率的影响3.1对小麦氮素利用效率的影响在不施氮和施氮量为180kg/hm2条件下，增加种植密度对氮素利用效率影响不显著，在施氮量为240kg/hm2条件下，中密度处理与低密度处理相比较，氮素利用效率无显著差异，均显著高于高密度处理。3.2对小麦氮素收获指数和籽粒含氮量的影响氮素利用效率为氮素收获指数和籽粒含氮量的比值。在不施氮和施氮量为180kg/hm2条件下，增加种植密度对氮素收获指数和籽粒含氮量影响均不显著，在施氮量为240kg/hm2条件下，中密度处理与低密度处理相比较，氮素收获指数无显著差异，显著高于高密度处理；籽粒含氮量无显著差异，均显著低于高密度处理。3.3开花后营养器官氮素向籽粒的转运及对籽粒的贡献在不施氮和施氮量180kg/hm2条件下，增加种植密度显著提高花前营养器官氮素贮藏再转运量、花后氮素生产量以及籽粒氮素积累量，花前营养器官贮藏氮素再转运率和对籽粒的贡献率无显著差异。施氮量240kg/hm2条件下，中密度与低密度相比，籽粒氮素积累量、营养器官贮藏再转运量和花后氮素同化量显著增加，花前营养器官贮藏氮素再转运率和对籽粒的贡献率无显著差异；高密度与中密度相比较，营养器官贮藏再转运量无显著差异，花后氮素生产量和籽粒氮素积累量显著增加，营养器官贮藏再转运率和对籽粒的贡献率降低。同一种植密度条件下，随施氮量的增加，花前营养器官氮素贮藏再转运量、花后氮素同化量和籽粒氮素积累量均增加，花前营养器官氮素贮藏再转运率以及对籽粒的贡献率降低，花后氮素同化量对籽粒的贡献率升高。4对小麦氮素利用率的影响氮素利用率为氮素吸收效率和氮素利用效率的乘积。在不施氮和施氮量为180kg/hm2条件下，随种植密度增加，氮素利用率显著增加，在施氮量为240kg/hm2条件下，中密度处理和高密度处理氮素利用率无显著差异，显著高于低密度处理。种植密度相同的条件下，随氮肥水平的提高，氮素利用率显著降低。5种植密度和氮肥水平对不同土层土壤硝态氮含量和氮素平衡的影响种植密度相同的条件下，随氮肥水平的提高，各土层硝态氮积累量增高，0-200cm硝态氮总积累量影响达到显著水平，表现为N240>N180>N0处理，土壤无机氮残留量，氮素表观损失量和损失率均增加；氮肥水平相同的条件下，随种植密度增加，各土层硝态氮积累量有降低趋势，0-200cm硝态氮总积累量影响达到显著水平，表现为低密度>中密度>高密度处理。土壤无机氮残留量，氮素表观损失量和损失率均降低。2011-2012年度，与播种前土壤硝态氮积累量相比较，不施氮条件下各密度处理0-200cm各土层硝态氮积累量均显著降低；施氮量为180kg/hm2的各密度处理0-40cm土层硝态氮积累量显著高于播种前，40-120cm土层硝态氮积累量与播种前基本平衡，120-200cm硝态氮积累量显著低于播种前；施氮量为240kg/hm2的各密度处理处理80-100cm土层硝态氮积累量显著高于播种前，其余土层表现规律与N180处理相同；2012-2013年度，与播种前比较，N0处理0-200cm各土层硝态氮积累量显著降低；N180和N240处理只有60-80cm土层硝态氮积累量显著高于播种前，其余土层均出现了氮素亏缺。年份之间试验结果的差异性与降雨量不同有关。更多还原

【Abstract】 The experiment was conducted with two common cultivars, Jimai22(high tilleringcapability) and Tainong18(low tillering capability) in2011-2013wheat growing season inYangzhuang village, Yanzhou, Shangdong. Considering the different tillering capacities, plantdensities of120,180, and240plants m–2were used for cultivar J22, while plant densities of135,270, and405plants m–2were utilized for T18. The N fertilization treatment was appliedat three levels using urea, i.e., no fertilization N (N0),180kg ha–1of N (N180, therecommended N input), and240kg ha–1of N (N240; local farmer’s fertilizer applicationamount). Since the plant density differed between cultivars, the field experiment was designedspecifically for each cultivar, which was established as a split-plot design of three replicateswith N input as the main plots and plant density as the subplot.15N-microplot experiment wasalso included in each plot. The results were as follows:1The effects of different plant density and nitrogen level on grain yield formation inwheat1.1The effects of different plant density and nitrogen level on dry matter accumulationAt the same nitrogen level, the dry matter at maturity was significantly increased withthe increasing plant density, with the increasing plant density, the dry matter accumulationduring the seeding–before winter, before winter-jointing, anthesis-maturity stage weresignificantly increased, the dry matter accumulation ratio during the seeding–before winterand before winter-jointing stage were significantly increased, the dry matter accumulationratio during the jointing-anthesis stage were significantly decreased; At the same plant density,the dry matter at maturity was significantly increased with the increasing nitrogen level, withthe increasing nitrogen level, the dry matter accumulation during the seeding–before winter,before winter-jointing, jointing-anthesis, anthesis-maturity stage were significantly increased,the dry matter accumulation ratio during the anthesis-maturity stage were significantlyincreased. 1.2The effects of different plant density and nitrogen level on grain yieldThe effects of N input, plant density, and all two-way interactions were significant ongrain yield for the two cultivars. An N input of0and180kg ha–1, no significant difference ofHI was observed among the plant density treatment, biomass and grain yield significantlyincreased with the increasing plant density. An N input of240kg ha–1, biomass significantlyincreased with the increasing plant density, no significant difference of grain yield wasobserved between the middle plant density and high plant density treatment, which aresignificantly higher than that of the low plant density.1.3The effects of different plant density and nitrogen level on grain filling parametersindexAn no N input, no significant difference of Tmax, D,T1,T2andT3were observed betweenthe plant density treatments, Wmax, GRmax and the mean grain filling rate showed adecreased trend and the grain weight at maturity significantly decreased with the increasingplant density. An N input of180kg ha–1, no significant difference of D and T1were observedbetween the plant density treatments, Tmax, T2andT3significantly increased, Wmax, GRmaxand the mean grain filling rate showed a decreased trend and the grain weight at maturitysignificantly decreased with the increasing plant density. An N input of240kg ha–1, Tmax,D,T1,T2andT3were all significantly increased, Wmax, GRmax and the mean grain filling rateshowed a decreased trend and the grain weight at maturity significantly decreased with theincreasing plant density.T18had a higher the mean grain filling rate compared to J22.1.4The effects of different plant density and nitrogen level on dry matter translocationAn no N input, both the translocation amount of dry matter stored in vegetative organsbefore anthesis and the dry matter accumulation amount after anthesis increased with theincreasing plant density, no significant difference of the translocation ratio and its contributionto grain of dry matter stored in vegetative organs before anthesis was observed among theplant density treatment. An N input of180kg ha–1, both the translocation amount of dry matterstored in vegetative organs before anthesis and the dry matter accumulation amount afteranthesis increased with the increasing plant density, the translocation ratio of dry matterstored in vegetative organs before anthesis was decreased with increasing plant density. An Ninput of240kg ha–1, the dry matter accumulation amount after anthesis was significantlyincreased with increasing plant density, the translocation amount of dry matter stored invegetative organs before anthesis was increased first and then decreased,the translocationratio of dry matter stored in vegetative organs before anthesis and its contribution to grainswere all decreased with increasing plant density. At the same plant density, the dry matter accumulation amount after anthesis and contribution to grain was significantly increased withthe increasing nitrogen level, the translocation amount and ratio of dry matter stored invegetative organs before anthesis and its contribution to grain were all decreased.2The effects of different plant density and nitrogen level on nitrogen uptake efficiency(UPE)2.1The effects of different plant density and nitrogen level on nitrogen accumulationAt the same nitrogen level, the nitrogen accumulation amount at maturity wassignificantly increased with the increasing plant density, with the increasing plant density, thenitrogen accumulation amount and ratio during the seeding–before winter, beforewinter-jointing, anthesis-maturity stage were significantly increased; At the same plant density,the nitrogen accumulation amount was significantly increased with the increasing nitrogenlevel, with the increasing nitrogen level, the the nitrogen accumulation amount during theseeding–before winter, before winter-jointing, jointing-anthesis, anthesis-maturity stage wereall significantly increased, the nitrogen accumulation ratio during the anthesis-maturity stagewere significantly increased.2.2The effects of different plant density and nitrogen level on nitrogen uptake efficiency(UPE)At the same nitrogen level, UPE was significantly increased with the increasing plantdensity, at the same plant density, UPE was significantly decreased with the increasing plantdensity, the interaction between N input and plant density was manifested at a highest UPEwith a combination of low N input and high plant density.2.3The effects of different plant density and nitrogen level on nitrogen uptake fromdifferent soil layerMean total15N uptake amount at depths0.2,0.6and1.0m were significantly decreasedwith the increasing depth of15N labeling. At the same nitrogen level, total15N uptake amountat depths0.2,0.6and1.0m were significantly increased with the increasing plant density, theabsolute amount and relative proportion of increased15N uptake increased with increasinglabeled depth. At the same plant density,15N uptake amount at depths0.2m and0.6m of Ninput of180kg ha–1were significantly lowerer than240kg ha–1,5N uptake amount at depths1.0m of N input of180kg ha–1were significantly higher than240kg ha–1. AGN was positivelyrelated with15N uptake amount at depths0.2and0.6m, UPE was positively related with15Nuptake amount at depths1.0m.3The effects of different plant density and nitrogen level on nitrogen utilizationefficiency (UTE) 3.1The effects of different plant density and nitrogen level on nitrogen utilizationefficiency (UTE)An N input of0and180kg ha–1, no significant difference of UTE was observed amongthe plant density treatment, An N input of240kg ha–1, no significant difference of UTE wasobserved between the low plant density and middle plant density treatment, which aresignificantly higher than that of the high plant density.3.2The effects of different plant density and nitrogen level on nitrogen harvest index(NHI) and grain nitrogen concentration (GNC)UTE could be calculated based on the ratio of the NHI to the GNC. An N input of0and180kg ha–1, no significant difference of NHI and GNC were observed among the plantdensity treatment, An N input of240kg ha–1, no significant difference of NHI was observedbetween the low plant density and middle plant density treatment, which are significantlyhigher than that of the high plant density. no significant difference of GNC was observedbetween the low plant density and middle plant density treatment, which are significantlylower than that of the high plant density.3.3The effects of different plant density and nitrogen level on nitrogen translocation inwheatAn no N input and N input of180kg ha–1, both the translocation amount of nitrogenstored in vegetative organs before anthesis and the nitrogen accumulation amount afteranthesis increased with the increasing plant density, no significant difference of thetranslocation ratio and its contribution to grain of nitrogen stored in vegetative organs beforeanthesis was observed among the plant density treatment. An N input of240kg g ha–1, themiddle plant density treatment increased the translocation amount of nitrogen stored invegetative organs before anthesis and the nitrogen accumulation amount after anthesis, but nosiginificant difference of the translocation ratio and its contribution to grain of nitrogen storedin vegetative organs before anthesis was observed, compared to the low plant densitytreatment. The high plant density treatment increased the the nitrogen accumulation amountafter anthesis, decreased the the translocation ratio and its contribution to grain of nitrogenstored in vegetative organs before anthesis, no siginificant difference of the amount ofnitrogen stored in vegetative organs before anthesis was observed,compared to the middleplant density treatment.At the same plant density, the translocation amount of nitrogen stored in vegetativeorgans before anthesis and nitrogen accumulation amount after anthesis was significantly increased with the increasing nitrogen level, the translocation ratio of nitrogen stored invegetative organs before anthesis and its contribution to grain were all decreased.4The effects of different plant density and nitrogen level on nitrogen use efficiency(NUE)An N input of0and180kg ha–1, NUE increased significantly with the increasing plantdensity, An N input of240kg ha–1, no significant difference was observed between the highplant density and middle plant density treatment, which are significantly higher than that ofthe low plant density.5The effects of different plant density and nitrogen level on NO3-N and soil nitrogenblanceAt the same plant density, soil NO3-N accumulation in0-200cm soil layer are increasedwith the increase of nitrogen level, which was presented as N240>N180>N0. the residualNmin and nitrogen apparent loss are increased significantly.At the same plant density, soilNO3-N accumulation in0-200cm soil layer are decreased with the increase of plant density,which was presented as low plant densty>middle plant density>high plant density,the residualNmin and nitrogen apparent loss are decreased significantly with the increasing plant density．In the2011-2012year, compared with soil NO3-N accumulation before sowing, at no Ninput, NO3-N accumulation of0-200cm soil layer at maturity of all the plant densitytreatments significantly increased, An N input of180kg ha–1, NO3-N accumulation of0-40cmsoil layer at maturity of all the plant density treatments significantly increased, no significantdifference of NO3-N accumulation of40-120cm soil layer at maturity of all the plant densitytreatments was observed, NO3-N accumulation of120-200cm soil layer at maturity of all theplant density treatments significantly decreased, An N input of240kg ha–1, NO3-Naccumulation of0-40cm and80-100cm soil layer at maturity of all the plant densitytreatments significantly increased, no significant difference of NO3-N accumulation of40-60cm soil layer at maturity of all the plant density treatments was observed, NO3-Naccumulation of100-200cm soil layer at maturity of all the plant density treatmentssignificantly decreased.更多还原