春玉米叶片SPAD值与氮含量及产量的相关性研究

通过田间小区试验,研究不同时期玉米叶片SPAD值与叶绿素、氮含量及产量的相关性,确定SPAD值测定的最佳叶位及时期。结果表明,上位叶SPAD值对氮素的敏感时期顺序为12叶期>10叶期>8叶期;穗位叶SPAD值对氮素的敏感时期顺序为抽雄期>灌浆期>蜡熟期。叶片SPAD值可以很好的反映植株叶绿素和氮含量及产量水平,以某一特定叶片的SPAD值来诊断春玉米氮素营养状况和推荐追肥时期时,10叶期是较为理想的测定时期;作为早期预测玉米产量的指标,12叶期为最佳时期。测定SPAD值方法简便、快捷,不破坏叶片生长,可作为早期预测玉米产量的指标。     

夏玉米叶片叶绿素含量的时空动态及其与植株含氮率关系的研究

在不同施氮水平下,研究了夏玉米郑单958叶片叶绿素含量(SPAD值)的时空动态变化及其与植株含氮率的关系。结果表明,夏玉米子粒生长期棒三叶SPAD值与棒三叶、全株总叶片及整株含氮率均有极显著线性相关关系。不同施氮水平子粒生长期叶片叶绿素含量的空间分布均以穗位叶为中心呈现出中间高两边低的趋势,SPAD值依次为中部叶>上部叶>下部叶。施氮可调节各部位叶片SPAD值或氮素含量,但并未改变其空间分布模式。不同施氮水平子粒生长期上部和中部叶片叶绿素含量随时间的动态变化总体上呈现先增大后减小的趋势,下部叶片的叶绿素含量则呈持续下降的趋势。夏玉米不同叶位叶片对氮肥的反应均表现在一定范围内(N≤207 kg/hm²),子粒生长期各叶片叶绿素含量随施氮量的增加而增加,当总施氮量增为276 kg/hm²时,各叶片叶绿素含量不再明显增加,相对来说中部叶比上部和下部叶对氮肥的反应更为敏感。     

施氮对灌浆期冬小麦不同叶片SPAD值及光合速率的影响

为了解不同施氮水平下小麦叶片叶绿素含量和光舍速率的变化，以冬小麦小偃22为供试材料进行小区试验，测定和分析了施氮后冬小麦灌浆期不同叶片的SPAD值及光舍速率。结果表明，在同一施氮水平下，小麦植株不同叶片SPAD值及光舍速率均为：旗叶〉倒二叶〉倒三叶〉倒四叶，说明小麦叶片叶绿素含量及光舍速率在植株上的分布特征相对固定，受施氮水平的影响较小。在施氮量小于90kg／ha时，小麦各叶片SPAD值随施氮水平的增加而增大；当施氮量超过90kg／ha时，小麦各叶片SPAD值变化趋势不明显。随施氮水平的提高，小麦叶片的光合速率呈现出先增加后下降的趋势，施氮量为135kg／ha时光合速率最高。     

不同氮肥水平下大豆叶片光谱反射率与叶绿素含量的相关性研究

用Unispec光谱分析仪和SPAD-502叶绿素仪测定不同生育时期不同氮肥水平大豆叶片光谱反射率及叶绿素含量,并分析了光谱植被指数与叶绿素含量的相关性。结果表明:不施氮肥处理光谱反射率高于施氮处理,随着施氮量的增加,大豆叶片光谱反射率下降,并初步断定结荚期是大豆氮素光谱营养诊断的敏感时期;随着氮肥水平的提高叶绿素含量增加;整个生育时期,除鼓粒期不施氮处理外其它处理的植被指数mND705与叶绿素含量均呈极显著正相关;在花期和结荚期,各处理的mSR705与叶绿素含量呈极显著正相关,PSSRc与叶绿素含量呈极显著负相关。     

叶面喷施氮肥对小麦SPAD值及产量的影响

为了解叶面施氮效应,在大田条件下,以农大1108和普冰79为材料,研究了在小麦抽穗期、开花期和灌浆期喷施浓度为1.0%、1.5%、2.0%、2.5%和3.0%的氮肥(尿素)对小麦旗叶SPAD值和籽粒灌浆动态及产量的影响。结果表明,与喷施等量清水的对照(CK)相比,喷施不同浓度氮肥后,两个小麦品种灌浆期旗叶的SPAD值均变化显著:在喷施氮肥浓度为1.0%(H1)、1.5%(H2)和2.0%(H3)时明显增加,在喷施氮肥浓度为2.5%(H4)和3.0%(H5)时明显下降,且H2和H3处理的小麦SPAD值在生育后期能保持一段时间的相对稳定状态,而CK呈下降趋势。两个小麦品种在喷施氮肥以后,H1、H2和H3处理的籽粒灌浆最大速率(Vmax)、籽粒灌浆平均速率(V)以及快增期籽粒灌浆平均速率(Vs)均明显提高,而H4和H5处理的Vmax、V和Vs明显下降。两个小麦品种的5个处理同CK相比,出现最大灌浆速率的时间(Tv)均有所提前,而且快增期持续时间(Tk)也明显缩短。两个小麦品种的产量、穗粒数和千粒重均表现为H3H2H1CKH4H5,且喷施氮肥处理均与CK差异显著。综合来看,叶面喷施浓度为2.0%的氮肥对小麦的增产效果最好。     

氮肥施用对旱地秸秆覆盖冬小麦旗叶生理特性的影响

为给旱地保护性耕作小麦水肥高效利用提供理论依据和建立合理的氮素管理模式,在渭北旱塬研究了秸秆覆盖下氮肥用量及施用时间对小麦旗叶光合特性及衰老的影响。结果表明,施氮量没有显著影响小麦花后旗叶的叶绿素相对含量(SPAD值)、光合速率和蒸腾速率,高氮用量明显增加小麦旗叶中丙二醛的累积,加速了旗叶衰老。氮素分次施用有延缓小麦旗叶SPAD值下降从而延缓旗叶衰老的作用,但是没有显著影响小麦旗叶的光合速率和蒸腾速率。秸秆覆盖较不覆盖显著提高了小麦旗叶的SPAD值、光合速率和蒸腾速率,并延缓了旗叶的衰老,进而提高了灌浆后期籽粒的灌浆速率,有增加千粒重的趋势。小麦籽粒产量变化范围为3 123~3 714kg·hm-2,试验年度氮素调控和秸秆覆盖均没有显著影响小麦的产量。     

不同形态氮素对弱筋小麦籽粒淀粉积累及其相关酶活性的影响

为给弱筋小麦优质高产高效栽培的合理氮肥运筹提供理论依据,在大田条件下研究了3种形态的氮素(酰胺态氮、铵态氮和硝态氮)对弱筋小麦豫麦50籽粒淀粉合成及其相关酶活性的影响.结果表明,施铵态氮能增加灌浆中后期籽粒总淀粉和支链淀粉积累量,保持较高的籽粒总淀粉和支链淀粉积累速率,而施酰胺态氮籽粒直链淀粉积累量和积累速率较高.施铵态氮有利于提高成熟期籽粒总淀粉、支链淀粉含量和支/直比例,而施酰胺态氮提高了直链淀粉含量.施硝态氮对小麦籽粒淀粉积累的调控效应介于施铵态氮和施酰胺态氮之间.施铵态氮和施硝态氮后旗叶蔗糖合成酶(SS)和灌浆中后期蔗糖磷酸合成酶(SPS)活性高,灌浆中后期籽粒蔗糖合成酶(SS)活性、籽粒蔗糖含量、可溶性淀粉合成酶(SSS)活性高,束缚态淀粉合成酶(GBSS)活性低,而施酰胺态氮则表现出相反的趋势.施硝态氮的旗叶蔗糖含量始终最低;与施酰胺态氮相比,施铵态氮旗叶蔗糖含量灌浆前中期低,而后期高.说明施铵态氮旗叶蔗糖合成能力强,源器官蔗糖向库运输迅速,籽粒库中糖源供应充足.因此,生产上可以通过改变氮素形态调节淀粉合成酶活性,进而调控淀粉的合成与积累.     

冬油菜叶片SPAD的时空分布和氮素诊断的叶位选择

在大田试验条件下测定分析不同施氮水平冬油菜关键生育期SPAD值的时空分布特征,并对不同叶位及叶片不同部位SPAD值与叶绿素含量、叶片含氮量、植株全氮含量及籽粒产量之间的相关性进行分析,探求应用SPAD仪诊断油菜氮素营养状况的最佳测试叶位及位点。结果表明,油菜主茎顶部4片完全展开叶SPAD值存在显著空间差异,增加施氮量能显著提高各叶位叶SPAD值,同时减少叶位间的差异;六叶期、蕾薹期以顶4叶（TL4）SPAD值对氮素的敏感性最大,初花期和盛花期则最低。不同部位间,六叶期和初花期以中部SPAD值对施氮量增加的响应最敏感,盛花期则最迟钝,蕾薹期介于顶部和基部之间。综合分析认为,应用SPAD仪监测油菜氮素营养状况的最佳测试叶位和位点为主茎顶4片完全展开叶中部,该部位SPAD值与叶绿素含量、叶片含氮量和植株全氮含量之间的相关性均达到显著或极显著水平,满足氮素营养快速诊断的要求。     

剪叶对豫农202籽粒灌浆与干物质积累的影响

为了探讨小麦新品种豫农202植株上部三片叶对籽粒干物质积累的影响,分别在小麦开花期和灌浆中期进行了不同的剪叶处理,分析了不同剪叶处理对剩余叶片的SPAD值、籽粒灌浆速率及籽粒干物质积累量的影响。结果表明,小麦开花期和灌浆中期剪叶后,植株上部三片叶的SPAD值在不同处理间具有明显差异,剪去部分叶片后剩余叶片的SPAD值均有所提高。从剪叶对籽粒灌浆速率和干物质积累量的影响来看,开花期剪叶的影响程度显著大于灌浆中期剪叶。不同剪叶处理间籽粒的灌浆速率和干物质积累量存在明显差异,开花期剪去倒一叶对灌浆速率具有较大的负向效应,其干物质积累量比对照降低了21.22%;剪去倒三叶对灌浆速率具有较大的正向效应,其干物质积累量增加了12.20%。灌浆中期剪叶后,所有剪叶处理的籽粒灌浆速率和干物质积累量均低于对照,且剪去的叶片越多灌浆速率和干物质积累量下降的幅度越大,同时剪去倒一叶和倒二后下降的幅度最大。     

施氮水平及方式对玉米冠层NDVI、氮含量、叶绿素和产量的影响

在不同施氮水平和方式（不追肥和拔节期追肥）的田间试验条件下,采集并测定玉米不同生育期的冠层归一化植被指数（NDVI）、叶片SPAD值、叶绿素含量、叶片全氮含量和产量,研究不同氮素水平下各指标间的相互关系。结果表明,在不同生育期玉米叶片叶绿素含量和冠层NDVI值均随施氮量的增加而增大,追肥能显著提高叶片叶绿素含量和冠层NDVI值,灌浆期玉米叶片叶绿素含量增加幅度最大。冠层NDVI值与叶片氮含量、叶绿素含量的相关系数在各生育期均达到显著或极显著水平,叶片SPAD值与叶绿素含量的关系同冠层NDVI值一致,两者均可以对玉米进行氮素营养的诊断,但NDVI比SPAD更具有快速可靠的优点。追肥较不追肥处理有明显增产效果,平均增产幅度为29.23%,最大增幅为44.13%。     

控释氮肥调控水稻光合功能和叶片衰老的生理基础

 以杂交水稻组合八两优100和威优46为试验材料，探讨了控释氮肥对水稻光合功能衰退和叶片衰老的调控机制。结果表明，控释氮肥对延缓早、晚稻功能叶的衰老和延长叶片的光合功能期均具有明显的效应。与施用尿素的处理相比，施用控释氮肥后，早、晚稻生育中、后期功能叶中的叶绿素含量得到显著的提高，且与尿素间的差异随着水稻生育进程而增大。不同时期控释氮肥处理功能叶的净光合速率也均显著地高于尿素处理。此外，施用控释氮肥能显著地提高生育中、后期功能叶中的SOD、POD等活性氧清除酶的活性，降低功能叶中的丙二醛含量。施用控释氮肥对功能叶中的IAA、ABA含量具有明显的调控效果，早、晚稻各时期控释氮肥处理的IAA含量均显著地高于尿素处理，而ABA含量显著地低于尿素处理。由于控释氮肥对水稻的上述调控机理，因而，在水稻上施用控释氮肥可以明显提高水稻产量。     

孕穗肥氮肥用量对抛栽杂交中稻后期光合性能及产量的影响

以杂交中稻皖稻153为材料,研究了孕穗肥氮肥用量对抛栽杂交水稻后期光合性能及产量的影响.结果表明:增加孕穗肥氮肥用量能提高后期叶片叶绿素含量,增加有效叶面积,保持后期有较高的光合潜能;增加二次分枝数、每穗粒数、着粒密度.杂交水稻皖稻153抛栽孕穗肥以施用尿素120 kg/hm<'2>左右为宜.     

Effects of Nitrogen Fertilizer Level on Chlorophyll Fluorescence Characteristics in Flag Leaf of Super Hybrid Rice at Late Growth Stage

To compare the effects of slow-release nitrogen fertilizer at six different levels on the flag leaf chlorophyll fluorescence characteristics of super hybrid rice,a field fertilization experiment was conducted with super hybrid rice Y Liangyou 1 as a test material.The photosynthetic electron transport rate (ETR),effective quantum yield (EQY),photochemical quenching coefficient (q P),and non-photochemical quenching coefficient (NPQ) of flag leaves were measured at the initial heading,full heading,10 d after full heading and 20 d after full heading stages.Results showed that the values of ETR,EQY and q P increased with rice development from initial heading to 20 d after full heading,whereas the NPQ decreased.During the measured stages,ETR,EQY and q P increased initially and then decreased as nitrogen application amount increased,but they peaked at different nitrogen fertilizer levels.The maximum ETR and EQY values appeared at the treatment of 135 kg/hm 2 N.In conclusion,the optimum nitrogen amount for chlorophyll fluorescence characteristics of super hybrid rice was 135 180 kg/hm 2.     

氮肥不同施肥方法对超高产水稻品种“沈农265”生理特性的影响

进行了氮肥不同施肥方法对超高产水稻品种"沈农265"主要生理性状的研究。试验结果表明:"沈农265"最佳施肥方法为施肥法A;CGR、NAR均与叶片叶绿素含量呈正相关;SLW与叶片含氮量呈显著正相关;在5个主要生育期叶氮、叶碳、叶绿素含量的最适值均与产量存在回归关系。     

Physiological Basis of Photosynthetic Function and Senescence of Rice Leaves as Regulated by Controlled-Release Nitrogen Fertilizer

The physiological mechanism of photosynthetic function and senescence of rice leaves was studied by using early rice variety Baliangyou 100 and late rice variety Weiyou 46, treated with controlled-release nitrogen fertilizer （CRNF）, urea and no nitrogen fertilizer. CRNF showed obvious effects on delaying the senescence and prolonging photosynthetic function duration of rice leaves. Compared with urea, CRNF could significantly increase the chlorophyll content of functional leaves in both early and late rice varieties, and this difference between the treatments became larger as rice growth progressed; CRNF increased the activities of active oxygen scavenging enzymes super oxide dismutase （SOD） and peroxidase （POD）, and decreased the accumulation amount of malondialdehyde （MDA） in functional leaves during leaf aging; Photosynthetic rate of functional leaves in CRNF treatment was significantly higher than that in urea treatment. The result also indicated that CRNF could effectively regulate the contents of indole-3-acetic acid （IAA） and abscisic acid （ABA） in functional leaves; IAA content was higher and ABA content was lower in CRNF treatment than those in urea treatment. Therefore, application of CRNF could increase the rice yield significantly due to these physiological changes in the functional leaves.     

Improvement of nitrogen management in rice paddy fields using chlorophyll meter (SPAD)

Optimum rate and timing application of nitrogen (N) fertilizer are most crucial in achieving high yield in irrigated lowland rice. In order to assess leaf N status, a semidwarf rice cultivar (Khazar) was grown with different N application treatments (0, 40, 80, and 120 kg N ha⁻¹ splited at transplanting, midtillering, and panicle initiation stages) in a sandy soil in Guilan Province, Iran, in 2003. The chlorophyll meter (SPAD 502) readings were recorded and leaf N concentrations were measured on the uppermost fully expanded leaf in rice plants at 10-day internals from 19 days after transplanting to grain maturity. Regression analysis showed that the SPAD readings predicted only 23% of changes in the leaf N concentration based on pooled data of leaf dry weight (N _dw) for all growth stages. However, adjusting the SPAD readings for specific leaf weight (SPAD/SLW) improved the estimation of N _dw, up to 88%. Specific leaf weight (SLW), SPAD readings, leaf area and weight as independent variables in a multiple regression analysis predicted 96% of the N _dw changes, while SPAD readings independently predicted about 80% of leaf N concentration changes on the basis of leaf area (N _a). It seems that chlorophyll meter provides a simple, rapid, and nondestructive method to estimate the leaf N concentration based on leaf area, and could be reliably exploited to predict the exact N fertilizer topdressing in rice.     

不同施肥水平对杂交水稻氮、磷、钾吸收积累的影响

为探索不同施肥量下2个杂交水稻植株氮、磷、钾的吸收积累特性,采用田间小区试验研究了两个杂交稻品种抽穗期和成熟期的植株氮、磷、钾吸收积累。结果表明,2个杂交水稻品种在不同施肥水平下,抽穗期和成熟期茎＋叶鞘、叶、穗各器官内的氮、磷、钾的含量无显著差异;抽穗期,叶的氮含量最高,茎＋叶鞘的磷、钾含量最高;成熟期,叶的氮含量、茎＋叶鞘的磷含量、穗的钾含量均下降。抽穗期,氮、钾吸收量及干物质量红泰优996高于粤优589,磷吸收量粤优589高于红泰优996;成熟期,氮、钾吸收量及干物质量粤优589高于红泰优996,磷吸收量2品种差异不明显。2个杂交水稻品种地上部植株对氮、磷、钾积累量比例的变幅范围均在高产水稻积累变幅范围内。     

水稻盆栽速效氮淋洗法及短期亏氮效果分析

【目的】 探索一种简易、有效的盆栽土壤速效氮淋洗方法,并分析水稻花前不同时期土壤氮亏缺对不同类型水稻主功能叶及植株花后氮积累的影响,以期为阐明水稻花后氮素积累、转运特征和大田生产减氮技术应用奠定研究基础。【方法】 比较了3种水稻盆栽土壤速效氮淋洗方法的减氮效果,同时探讨了水稻花前14 d和花前3 d短期亏氮对籼粳杂交稻甬优12号、籼型杂交稻中浙优1号上3叶SPAD值、氮浓度和花后植株含氮量的影响。【结果】 通过淋洗结构+沙土混合基质方法进行3次淋洗,即可将土壤中85.6%的硝态氮和67.1%的铵态氮洗脱;水稻花前处理后,土壤硝态氮和铵态氮含量分别降低42.1%~59.3%和35.0%~43.9%,可实现预期的土壤减氮效果,短期内对土壤速效氮供应能力形成有效抑制。花前土壤氮亏缺导致甬优12上3叶SPAD值和氮浓度以及齐穗后10 d植株茎鞘、叶、穗和单株含氮量显著降低,且茎鞘、穗和单株含氮量在两淋洗处理间差异显著。花前14 d淋洗减氮导致中浙优1号上3叶SPAD值和氮浓度以及齐穗后10 d单株和穗部含氮量显著下降,花前3 d淋洗处理则对中浙优1号上3叶氮浓度和植株氮积累量几乎无影响。【结论】 水稻对花前14 d氮亏缺的敏感性显著高于花前3 d,植株不同叶位叶片的叶色和氮浓度对土壤氮亏缺敏感度由下而上增强,两时期土壤氮亏缺对籼粳杂交稻甬优12的影响均远大于籼型杂交稻中浙优1号,意味着籼型杂交稻中浙优1号花后对土壤速效氮需求明显降低,而籼粳杂交稻甬优12减数分裂期后对土壤速效氮存在更高需求。     

Variation of Soil Microbial Biomass and Enzyme Activities at Different Growth Stages of Rice （Oryza sativa）

A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rate, soil microbial metabolic quotient, soil enzyme activities, chlorophyll content, proline content and peroxidase activity （POD） in rice leaf at different growth stages. The soil Cmic, Nmic and soil respiration rate significantly increased at the early stage and then declined during rice growth, but ascended slightly at maturity. However, soil metabolic quotient declined at all the stages. Soil urease activity increased at first and then decreased, while acid phosphatase and dehydrogenase activities descended before ascended and then descended again. Soil urease activity and acid phosphatase activity showed a peak value at the tillering stage about 30 days after rice transplanting, but the peak value of dehydrogenase activity emerged at about 50 days after rice transplanting and the three soil enzymatic activities were significantly different at the different developmental stages. As rice growing, chlorophyll content in rice leaf descended at the early stage then ascended and a peak value appeared at about the 70th after rice transplanting, after that declined drastically, while POD activity increased gradually, but proline content declined gradually. There was a slight relation between rice physiological indices and soil biochemical indices, which indicated that soil biochemical characteristics were affected significantly by rice growth in the interaction system of the rice. soil and microorganisms.     

红壤稻田钾肥施用量对超级稻生长及产量的影响

 以超高产水稻中浙优1号、甬优9号为材料,研究土壤不同钾素水平(50 mg/kg、90 mg/kg)及钾肥用量(0、75、150、225 kg/hm2氯化钾)对水稻生长和产量的影响。土壤不同钾素水平对穗数、成穗率、每穗粒数、着粒密度、株高、叶片叶绿素含量（SPAD值）和光合速率有显著影响,差异达显著水平;不同时期施用钾肥对产量的贡献依次为：基肥>分蘖肥>穗肥,产量差异达到3%~10%;随着施钾量增加植株高度明显增加,中浙优1号上表现更为明显,且随着施钾量增加,茎秆加粗,特别是基部节间粗度增加尤为明显。施钾与不施钾相比,两个品种产量分别增加5.6%和8.8%,但产量增加并不与施钾量成正比,不同施钾水平间产量差异不显著。