【作者】 王成雨；

【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， 2011， 博士

【摘要】 试验采用大穗型品种泰农18（T18）和多穗型品种山农15（S15）为供试材料,2008-2009年两个品种设3个氮肥水平0、180、240kg·hm^-2,分别为N0、N180、N240;和两个种植密度150×10⁴hm^-2、225×10⁴hm^-2基本苗,分别为D150、D225。2009-2010年根据2008-2009年的试验结果,泰农18增加了1个氮肥水平300kg·hm-2和1个种植密度300×10⁴hm^-2基本苗,分别为N300和D300。研究了氮肥水平和种植密度互作条件对冬小麦群体动态变化和产量、冠层结构与光合性能、小麦茎秆结构特征与抗倒性能、土壤硝态氮时空分布以及肥料利用效率的影响,主要研究结果如下:1氮肥和密度对冬小麦群体动态变化和产量的影响在本试验条件下,两个不同穗型的小麦品种群体数量均随氮肥水平和种植密度的增加而增加。大穗型品种T18叶面积系数、干物质积累量随氮肥水平和种植密度的增加而增加;中穗型品种S15叶面积系数、干物质积累量变化趋势在生育阶段的前中期与大穗型品种T18一致,但生育阶段的后期,高氮肥水平和高密度处理密度反而低于低氮肥水平和低密度处理,但都高于不施氮处理。两个不同穗型小麦品种的单位面积穗数均随氮肥水平和种植密度的增加而增加。大穗型品种T18千粒重随氮肥水平的增加而降低,随种植密度的增加先增加后降低;中穗型品种S15千粒重随氮肥水平和种植密度的增加而降低。大穗型品种T18穗粒数随氮肥水平的增加和种植密度的降低而增加;中穗型品种S15的穗粒数表现为高氮肥水平和高密度处理密度反而低于低氮肥水平和低密度处理,但都高于不施氮处理。氮肥水平和密度处理对产量的影响存在显著的交互效应,对于大穗型品种T18来说,在同一密度条件下产量随氮肥水平的增加而增加,在同一氮肥水平条件下产量随密度的增加而增加;对于中穗型品种S15来说,在同一密度条件下产量随氮肥水平的增加先增加后降低,在同一氮肥水平条件下产量随密度的增加而降低。大穗型品种T18以N300D300处理产量最高但与N240D225、N180D225差异不显著;中穗型品种S15的N180D150处理产量显著高于其他处理。增加氮肥水平和降低密度不利于花前贮藏同化物向籽粒的运转。除大穗型品种T18低氮低密度（N180D150）处理外,两个品种的经济系数施氮处理间均差异不显著但显著低于不施氮处理,合理氮肥水平和种植密度提高产量是通过提高生物量,而不是通过提高经济系数来实现的。2氮肥和密度对冠层结构与光合性能的影响对于大穗型品种T18来说,与不施氮处理相比,施氮可以增加旗叶叶面积但施氮处理间差异不显著,同一氮肥水平下受密度影响不大;旗叶厚度、含氮量、叶绿素含量、净光合速率、气孔导度、蒸腾速率、PSII最大光化学效率、PSII实际光化学效率、SOD、POD、CAT活性均随氮肥水平的增加和密度的降低而升高;胞间CO2浓度随氮肥水平和密度的增加而增加。对于中穗型品种S15来说,随氮肥水平和种植密度的增加,旗叶叶面积显著增加;旗叶厚度、含氮量、叶绿素含量、净光合速率、气孔导度、蒸腾速率、PSII最大光化学效率、PSII实际光化学效率、SOD、POD、CAT活性均随氮肥水平的增加先增加后降低,随密度的增加而降低;胞间CO2浓度随氮肥水平和密度的增加而增加。两个穗型品种的旗叶净光合速率与旗叶厚度、叶绿素、含氮量之间呈显著或极显著的正相关关系。大穗型品种T18的旗叶净光合速率与旗叶叶面积呈呈显著或极显著的正相关关系,但中穗型品种S15的旗叶净光合速率与旗叶叶面积相关关系不显著。大穗型小麦品种T18的WLAI和TLAI整个灌浆期内随氮肥水平和种植密度的增加而增加,整个生育期内N240D225>N180D225>N240D150>N180D150>N0D225>N0D150。中穗型小麦品种S15在灌浆前中期（开花-花后14天）WLAI和TLAI的变化趋势与大穗型小麦品种T18相似。但灌浆中后期（花后14天-成熟）,WLAI和TLAI在同一种植密度下随氮肥水平的增加先增加后降低;在低氮水平下,高密度处理WLAI和TLAI高于低密度处理,在中氮和高氮水平下趋势相反,灌浆中后期WLAI和TLAI表现为N180D150>N180D225>N240D150>N240D225>N0D150>N0D225。对于大穗型品种T18来说,LLAI在同一密度水平下随氮肥水平和种植密度的增加而增加,整个灌浆期内N240D225>N180D225>N240D150>N180D150>N0D225>N0D150。对于中穗型品种S15来说,LLAI在同一密度条件下随氮肥水平的增加先增加后降低;高密度处理LLAI在同一氮肥水平条件下低于低密度处理,N180D150>N180D225>N240D150>N240D225>N0D150>N0D225。对于大穗型品种T18来说,CAP在同一密度水平下随氮肥水平和种植密度的增加而增加,N240D225、N180D180、N240D150之间差异不显著,但都显著高于N180D150、N0D225、N0D150。对于中穗型品种S15来说,CAP在同一密度条件下随氮肥水平的增加先增加后降低;高密度处理CAP在同一氮肥水平条件下低于低密度处理,N180D150最高,且显著高于其它处理。在下部叶片持绿期内,冬小麦下部叶片叶面积系数（LLAI,下部两片叶）与群体净光合速率（CAP）和产量呈极显著的正相关关系;从开花到花后14天之前,上部叶片叶面积系数（TLAI,上部三片叶）和全部叶面积系数（WLAI,下部叶片和上部叶片之和）与群体净光合速率（CAP）和产量并不呈必然的显著正相关关系（T18显著正相关,S15相关不显著）,但花后14天至成熟,两个品种的TLAI和WLAI均与群体净光合速率和产量呈显著的正相关关系。3氮肥和密度对中穗型品种S15茎秆结构特征与抗倒性能的影响施氮水平和种植密度间存在显著的互作效应,施氮水平由180 kg·hm^-2增至240 kg·hm-2或种植密度由150×10⁴·hm^-2增加到225×10⁴·hm^-2,中穗型小麦品种S15茎秆重心高度、基部节间长度显著提高,基部节间直径、厚度、充实度、机械强度和抗倒指数显著降低,同时茎秆基部节间纤维素含量、木质素含量显著减少,含氮量显著升高,碳氮比（C/N）以及木质素合成相关酶活性显著降低。逐步回归分析表明,在影响小麦抗倒性能方面,氮肥水平的作用大于种植密度。本试验条件下,虽然氮肥水平为180 kg·hm^-2、种植密度为150×10⁴ hm^-2的处理穗数较低,但穗粒数、千粒重显著高于其它处理,产量最高。因此,降低氮肥用量至180 kg·hm^-2的同时降低种植密度至150×10⁴ hm^-2,可在增强植株抗倒伏能力的同时获得高产。4施氮对土壤硝态氮时空分布的影响小麦生育前期（出苗-拔节）,土壤耕层NO₃^--N含量较高。随施氮量增加,土壤0-40cm土层中NO₃^--N含量显著增加,而40cm-200cm土层NO₃^--N含量处理间差异不明显。小麦生育中后期（拔节-成熟）NO₃^--N累积峰明显下移,处理间相比较表现为随施氮水平的增加土壤NO₃^--N含量显著升高。年季间比较,2009-2010生长季低氮处理0-200cm土层硝态氮含量显著低于2008-2009生长季的低氮处理0-200cm土层硝态氮含量,连续减量施氮可以降低土壤硝态氮含量。5氮肥和密度互作对肥料利用效率的影响在冬小麦生育阶段的前中期,两个小麦品种的氮、磷、钾吸收量均随氮肥水平和种植密度的增加而增加;在小麦生育阶段的中后期,大穗型品种T18的氮、磷、钾吸收量仍表现为随氮肥水平和种植密度的增加而增加;但中穗型品种S15表现为在同一种植下随氮肥水平的增加先增加后降低,在同一氮肥水平下随种植密度的增加而降低。氮、磷、钾吸收量呈显著或极显著的正相关关系,氮素可以促进磷和钾的协同吸收。对于大穗型品种T18和中穗型品种S15来说,在同一密度条件下,氮素养分利用效率（NUE）、氮肥农学效率（AEN）、氮肥生理效率（PEN）和氮肥偏生产力（PFPN）均随氮肥水平的增加而降低。大穗型品种T18在同一氮肥水平条件下,NUE、AEN、PEN和PFPN随种植密度的增加先增加后降低,中穗型品种S15在同一氮肥水平条件下,REN、AEN、PEN和PFPN则随种植密度的增加而降低。对于大穗型品种T18来说,适当增加种植密度可以同步提高NUE、AEN、PEN和PFPN;对于中穗型品种S15来说,增加密度不利于NUE、AEN、PEN和PFPN的提高。对于两个穗型的品种来说,在同一种植密度条件下,磷素养分利用效率（PUE）和钾素养分利用效率（KUE）均随氮肥水平的增加而降低;大穗型品种T18磷肥偏生产力（PFPP）和钾肥偏生产力（PFPK）随氮肥水平的增加而提高,中穗型品种S15的PFPP和PFPK随氮肥水平的增加先增加后降低。大穗型品种T18的PUE、PFPP、KUE和PFPK随种植密度的增加先增加后降低,中穗型品种S15的PUE、PFPP、KUE和PFPK随种植密度的增加而降低。说明,在本试验条件下,对于大穗型品种T18来说,适当增加种植密度可以同步提高PUE、PFPN、KUE、PFPK;对于中穗型品种S15来说,增加密度不利于KUE、AEN、PEN和PFPN的提高。综合考虑产量、冠层结构与光合性能之间的关系、形态特征与抗倒性能之间的关系、土壤硝态氮的变化以及肥料利用效率等以上结果,大穗型品种T18以N180D225处理,中穗型品种S15以N180D150处理是高产、稳产、生态、高效的氮肥密度组合方式。更多还原

【Abstract】 In this study, T18, a winter wheat variety with multi-grain number per spike, and S15, a winter wheat variety with middle grain number per spike, were used as experimental materials for investigating the effects on the changes of population and grain yield, canopy architecture and ability of photosynthesis, the characteristic of culm and lodging resistance, the changes of NO3--N content in 0-200cm soil profile with time and space and fertilizer use efficiency under different nitrogen rate and plant density. The main results were as follows:1 Effects of nitrogen rate and plant density on the changes of population and grain yield in two types of wheat cultivars.The population of two types of wheat cultivars increased with the increasing of nitrogen rate and plant density in this study. The LAI and drymatter accumulation increased with increasing of itrogen rate and plant density for T18 in the whole growing stage. These were in same with T18 for S15 only during early and middle growing period but during late growing period the LAI and drymatter accumulation of high nitrogen and high density treatments were less than that of low nitrogen and low density treatments which both more than no nitrogen application treatments.With nitrogen rate and plant densit increasing, the total ears per unit area increased. Weight per 10³ kernels of T18 decreased with nitrogen rate increasing, and increased first and then decreased with plant density increasing. For S15, Weight per 10³ kernels of high nitrogen and high density treatments is less than that of low nitrogen and low density treatments which both more than no nitrogen application treatments. There existed significant interaction on grain yield between nitrogen rate and plant density. In the same plant density, the yield of T18 increased with the nitrogen rate increasing; in the same nitrogen rate, the yield of T18 increased first and then decreased with plant density increasing. For S15, the yield increased first and then decreased with nitrogen increasing in the same plant density; in the same nitrogen rate, the yield decreased with the plant density increasing. The treatment N300D300 gained the highest yield but was not significant to N240D225 and N180D225 for T18. For S15, the treatment N180D150 gained the highest yield and was significant to other treatments.Decreasing nitrogen rate and increasing plant density made reserves in vegetable organs before anthesis of wheat plant for translating to grain. Except for treatment of N180D150 the economic coefficient was not signicant among treatments of nitrogen application but all higher significantly than the treatments of no nitrogen application. So the yield elevation was achieved by increasing of dry matter weight not by improving the economic coefficient.2 The effects of nitrogen rate and plant density on canopy architecture and ability of photosynthesisFor T18, the flag leaf area of nitrogen application treatment was bigger than that of no nitrogen treatment. The flag leaf area was not affected significantly by plant density in the same nitrogen. The weight/area, nitrogen content, chlorophyll content, Pn, Cond, Tr, Fv/Fm,ΦPSII, SOD activity, POD activity, and CAT activity increased with the increasing of nitrogen rate and the decreasing of plant density; Ci of T18 increased with nitrogen rate and plant density increasing. The flag leaf area of S15 increased with the increasing of nitrogen and plant density. For S15, the weight/area, nitrogen content, chlorophyll content, Pn, Cond, Tr, Fv/Fm,ΦPSII, SOD activity, POD activity, and CAT activity increased first and then decreased with the increasing of nitrogen rate but decreased always with increasing of plant density; Ci of S15 increased with nitrogen rate and plant density increasing.There existed significant positive correlation between the Pn of flag leaf and the weight/area, nitrogen content, chlorophyll content in two types of wheat cultivars. For T18, there existed significant positive correlation between the Pn and area of flag leaf but not for S15.WLAI and TLAI increased with nitrogen rate and plant density increasing, and it was showed that N240D225>N180D225>N240D150>N180D150>N0D225>N0D150during the entire growing stage which was from anthesis to 14 days after anthesis for T18. For S15, they were in same with T18 during the early and middle filling stage. But during the late filling stage which from14 days after anthesis to maturity, WLAI and TLAI increased first and then decreased with the nitrogen rate increasing in the same plant density; and WLAI and TLAI of high density treatment was higher than low density treatment when no nitrogen applied, but it was contrary to the nitrogen application treatments. It was showed that N180D150>N180D225>N240D150>N240D225>N0D150>N0D225 for WLAI and TLAI of S15 during the late filling stage.For T18, LLAI increased with the increasing of nitrogen rate and plant density, and it was showed that N240D225>N180D225>N240D150>N180D150>N0D225>N0D150 in the whole filling stage. For S15, LLAI increased first and then decreased with increasing of nitrogen rate in the same plant density; LLAI decreased with plant density increasing in the same nitrogen rate, and it was showed that N180D150 > N180D225 > N240D150 >N240D225>N0D150>N0D225 during the whole filling stage.For T18, CAP increased with the increasing of nitrogen rate and plant density. There was no significant difference among N240D225、N180D180、N240D150, but they were all significant higher than 180D150、N0D225、N0D150. For S15, CAP increased first and then decreased with nitrogen rate increasing, CAP of high plant density was lower than that of low plant density in the same nitrogen rate. The CAP of N180D150 was higher significantly than other treatments.Lower leaf area index （LLAI） was positively significantly correlated with CAP and grain yield during the lower leaf stay-green stage , which consists of the lower two layers of leaves on the stem ; Top leaf area index （TLAI） consists of the top three layers of leaves on the stem and Whole leaf area index （WLAI） which consists of all of the leaves on the stem were positively significantly correlated with CAP and grain yield for T18 but not for S15 so the relationship were not certainly within 14 days after anthesis; TLAI and WLAI were positively significantly correlated with CAP and grain yield for two kind of wheat from 14 days after anthesis to maturity.3 Effects of nitrogen rate and plant density on the characteristic of culm and lodging resistance for S15The effects of nitrogen rate and plant density on lodging resistance related traits including morphological character, chemical components of basal internode, culm lodging resistance index, enzyme activities of lignin metabolism and grain yield of winter wheat were investigated. The results showed that grain yield were decreased and culm height of center of gravity and length of basal internode were raised as nitrogen rate increased from 180 kg·ha-1 to 240 kg·ha-1 or plant density increased from 150 ha-1 to 225 ha-1, while diameter, thickness, filling degree, mechanical strength of basal internode, and culm lodging resistance index were reduced. At the same time, cellulose content, lignin content, C/N ratio of basal internode were decreased but nitrogen content was increased with the increase of nitrogen rate or plant density. There existed significant interaction on lodging resistance between nitrogen rate and plant density, which led to worst lodging resistance in wheat plant under higher nitrogen rate plus higher plant density. Stepwize regression analysis indicated that nitrogen rate played a more important role in affecting lodging resistance compared with plant density. The highest kernels per spike, 1000 kernel weight and grain yield were gained with 180 kg·ha-1 nitrogen application rate plus 150 ha-1 basic seedlings. Therefore, proper combination with 180 kg·ha-1 nitrogen application rate plus 150 ha-1 basic seedlings could not only improve lodging resistance but also raise grain yield.4 Effects of nitrogen application on the changes of NO₃^--N content in 0-200cm soil profile with time.During the early growing stage, Content of NO₃^--N in 0-40cm soil profile is higher relatively. With nitrogen rate increasing, content of NO₃^--N in 0-40cm soil profile increased significantly but not significantly for that in 40-200cm. During the middle and late state, the peak value of NO₃^--N accumulation moved downwards obviously. The content NO₃^--N of 2009-2010 growing season was lower significantly than that of 2008-2009 growing season. It was showed reducing nitrogen amount successively in two growing seasons could decrease the content of NO₃^--N effectively.5. Efffect of interactions of nitrogen and density on fertilizer use efficiencyIn the early and middle growing stages of two types of wheat cultivars, nitrogen, phosphorus and potassium absorption volume improved with increasing of nitrogen rate and plant density. In the late stage of wheat, N, P and K uptake of T18 were still improved with increase of density and nitrogen, but for S15 showed that N, P and K uptake increased first and then decreased in the same plant density. There were significant positive correlations among N, P, K, and uptake of nitrogen could improve the absorption of phosphourus and potassium.In the same density condition, NUE, AEN, PEN and PFPN with the nitrogen rate increasing are increased for two types of wheat cultivars. In the same nitrogen levels, NUE, AEN, PEN and PFPN of T18 with the increasing of density increased and then decreased. NUE, AEN, PEN sand PFPN of S15 with the increasing of density decreased. For T18, increasing density appropriately could be increased NUE, AEN, PEN and PFPN at the same time, but increasing density was not conducive to improve NUE, AEN, PEN and PFPN of S15.For two ear types of wheat, in the same density conditions, PUE and KUE decreased with increasing of nitrogen rate. PFPP and PFPK of T18 increased with increasing nitrogen rate, but for S15 PFPP and PFPK increased and then decreased with nitrogen rate increasing. PUE, PFPP, KUE and PFPK of T18 increased and then decreased with the increase of density, but PUE, PFPP, KUE and PFPK of S15 decreased with the increasing of plant density in the same nitrogen rate.Under the experimental conditions, for T18, increasing density appropriately could increased PUE, PFPP, KUE, PFPK at the same time, but increasing density was not conducive to improve PUE, PFPP, KUE, PFPK of S15.As far as the relationship between yield, canopy structure and photosynthetic performance, between the morphological characteristics and lodging, changes of soil nitrate and fertilizer use efficiency were considered, N180D225 treatment of T18 and N180D150 of S15 were high-stable yield, ecological and efficient treatments of nitrogen and density combinations.更多还原