【作者】 钱永德；

【导师】 左豫虎； 郑桂萍；

【作者基本信息】 黑龙江八一农垦大学 ， 作物栽培学与耕作学， 2012， 博士

【摘要】 氮、镁都是水稻正常生长发育所必须的营养元素,是植株的重要组成成分,同时以多种方式参与体内各种生理生化过程,对促进植物的生长发育和新陈代谢起着重要的作用。镁是叶绿体的组成部分,对稻米品质和产量也有重要影响。本文以水稻（龙粳20号）为研究对象,在大田正常生产条件下,采用常规施肥方法,通过裂区试验设计方法设计不同氮、镁肥量构建不同群体,围绕产量和品质指标,系统研究了氮、镁元素对水稻个体养分吸收、积累、生理特性及群体质量指标、产量构成因素的影响（以下氮为尿素、镁为硫酸镁,均为商品用量）。本研究取得以下进展:1.施用氮镁肥料对植株养分含量的影响氮、镁肥料用量明显影响植株体内氮镁营养的含量、积累及物质生产。通过对植株各部位氮、镁含量测定,结果表明,施用氮肥明显提高地上营养体全氮含量和蜡熟末期地上营养体全镁含量,相关系数分别为0.9241和0.8276,而与籽粒中氮、镁含量无明显相关;施用镁肥对各部位氮镁养分含量无明显影响;叶片中氮镁含量提高均促进地上干物质增加,施氮的营养作用明显大于镁,镁含量与根冠比呈反比,镁缺乏时根冠比明显增大;氮镁配合施用大多表现为低镁水平提高氮镁含量与积累,高氮、高镁肥用量植株中氮、镁养分含量和积累量减少。公顷施氮肥450.0kg+镁肥112.5kg处理比公顷施氮肥450.0kg处理叶片镁含量提高3.8%、镁积累量提高20.3%,公顷施氮450.0kg+镁450.0kg处理叶片镁含量比公顷施氮450.0kg处理下降14.4%、镁积累量下降16.5%,表明氮镁同时过量会明显抑制镁向叶片中运转或吸收,降低养分积累量;在植株体养分含量上表现为低镁水平时氮镁含量共同促进,高氮、高镁则有一定抑制。肥料单独施用时,地上营养体内氮、镁营养含量表现为明显相互促进效应,养分配合施用时,全氮含量较低时镁含量随氮含量提高也随之增多,当地上营养体全氮含量超过35.8g·kg^-1后镁含量随氮含量提高略有降低。2.施用氮镁肥料对光合作用的影响氮镁适当配比能有效提高净光合速率,每公顷施氮量225.0kg和337.5kg分别配合施用112.5kg、225.0kg、337.5kg镁肥处理能明显提高孕穗期叶片净光合速率,增幅为4.3%²9.7%。3.施用氮镁肥料对群体茎数动态的影响氮镁配合施用可以有效提高收获穗数,公顷分别施氮225kg、337.5kg和450kg时,均配合施镁225kg,收获穗数比不施镁肥分别增加15.0%、10.0%和14.8%;施镁量与籽粒中的养分比值N/Mg和N/（MgK）均呈单峰曲线,适当施镁能有效提高籽粒N/Mg和N/（MgK）;孕穗期叶片中的镁含量与有效蘖率及分蘖穗比率均呈显著正相关,适当范围内提高地上营养体内N/Mg能有效提高产量。4.施用氮镁肥料对产量与产量构成因素的影响两年试验结果表明,养分单独施用时,低镁量表现增产;产量随施氮增加明显增多,氮肥过高增产幅度减小,甚至有减产趋势。氮镁配合施用后,氮对产量效应大于镁肥,对产量起主导作用,镁及其与氮肥的互作效应对产量无明显影响。提高地上营养体氮镁含量均明显提高产量,氮含量过高时产量反而有降低趋势。施氮量与单位面积穗数、每穗粒数及稻谷产量均呈显著正相关,与结实率和千粒重呈极显著负相关;镁肥施用量与水稻产量构成各因素及产量的相关性均未达到显著水平;提高孕穗期叶片氮、镁含量均能有效提高每穗粒数。公顷施氮337.5kg处理配合施用镁肥112.5³37.5kg均有不同程度增产效果。5.施用氮镁肥料对稻米品质的影响施氮量与籽粒中N/（MgK）和N/Mg相关不明显,施镁量与N/（MgK）和N/Mg相关显著,适量施镁可有效提高N/（MgK）和N/Mg进而提高整精米率,但N/（MgK）比值过高时整精米率趋于下降。两年试验结果表明,垩白率与整精米率呈显著负相关。氮镁配合施用以后,氮对垩白率的影响显著;镁对垩白率和整精米率的影响达到显著水平,高氮肥水平时配合公顷施镁225.0kg³37.5kg明显降低稻谷垩白率、提高整精米率。肥料单独施用时,食味随施镁量增多呈先升高然后降低的趋势,低镁或高镁均降低食味;单独施氮时表现低氮肥提高食味,高氮肥食味明显降低。高氮配合低镁处理有提高食味的效果,公顷施氮337.5kg+镁112.5kg和公顷施氮450.0kg+镁112.5kg处理均比不施镁肥处理的食味值高:2009年分别提高8.2%和2.3%,2010年分别提高3.8%和1.4%。6.施用氮镁肥料对群体整精米产量的影响整精米产量是稻谷产量与品质的综合评价指标之一,本研究结果表明,产量构成因素中的单位面积穗数和每穗粒数分别与整精米产量呈显著正相关,结实率和粒重分别与整精米产量呈负相关。养分单独施用时,表现低镁水平明显提高整精米产量,施氮对提高整精米产量作用明显。氮镁配合施用后,氮、镁及二者互作对整精米产量影响显著,氮水平越高整精米产量越多,氮肥过量整精米产量有减少趋势,高氮高镁处理不利于整精米率提高。公顷施氮337.5kg+镁112.5kg和公顷施氮337.5kg+225.0kg处理整精米产量2009年和2010年分别比不施镁肥处理提高1.9%、5.0%和9.8%、16.4%。综上,氮镁互作对水稻植株分蘖期、齐穗期干物重、孕穗期根干重、基部第二节间充实度、碳氮代谢、群体茎数动态及源库关系均有显著影响。氮、镁营养相互作用关系复杂,既有促进效应,也有抑制效应,不同环境表现有差异,相互促进效应在低氮条件下表现明显,高氮高镁时地上营养体全氮含量超过35.8g·kg^-1后镁含量反而降低。表明氮、镁营养比例与平衡在不同肥料施用量的条件下会出现变化。目前在我国农业生产中氮肥施用远比镁肥施用普遍,然而氮肥的施用增加了水稻对镁营养的需求,大量施用氮肥会诱导水稻缺镁。因此,建议在大田生产中合理施用氮肥的同时要重视镁营养的及时补给以维持水稻对养分的均衡吸收,实现水稻高产优质目标。更多还原

【Abstract】 Nitrogen（N）and Magnesium（Mg）were the essential nutritional elements for the normal plant growth and development of rice,which were the important components participating in various physiological and biochemical processes of rice plant,playing an important role in promoting plant development and metabolism.Mg was a component of chloroplast,which could influence the yield and quality of rice as well.The effects of N and Mg on the nutrient content,accumulation,physiological characters,indexes of population quality and yield components was systematically studied in this paper,using LONGJING 20（Oryza sativa L.）as research object and popular fertilizing methods in the field to design different rice populations through the crack zone experiment design（The following amount of N and Mg are all the commodity by urea and Magnesium sulfate respectively for standard）.The main results were as follows: 1.Effects on plant nutrient content of applying N and MgThe plant nutrient content,accumulation and mass production were significantly influenced by the applying amount of N and Mg.The content of N and Mg in every part of the rice plant indicate that the content of N in the over-ground plant and Mg in wax medium-stage plant were significantly improved by the application of N（r = 0.9241 and r = 0.8276）,but the content of N and Mg in grain was not related to the application of N.The increase of dry matter weight in the over-ground plant was promoted by the increased content of N and Mg.The nutritional role of N was obvious lager than Mg.There was an inverse proportion between content of Mg and the value of root/canopy,the value of root/canopy was significantly increased when the amount of Mg was lacked.The content and accumulation of N and Mg was improved by the cooperated application of them when the amount of Mg is little.When the applying amount of N and Mg was abound,it impaired the content and accumulation of them.The content of Mg in the treatment（450.0kg N + 112.5 kg Mg）was more than the treatment（450.0kg N）,the increased ratio was 3.8%,and the accumulated amount was improved at 20.3%.The content of Mg in the treatment（450.0kg N+ 450 kg Mg）was less than the treatment（450.0kg N）,the decreased ratio was 14.4%,and the accumulated amount of Mg was decreased at 16.5%.It indicated that the transfer or content of Mg were restrained,the accumulated amount of nutrient was decreased due to the simultaneously excessive application of N and Mg.During the course of nutritional content,the content of N and Mg was jointly promoted at the lower amount of Mg and inhibited contrarily.The nutritional content of N and Mg for over-ground plant was reciprocally promoted applying fertilizer singly.When the cooperated application of N and Mg was applied,the content of Mg was increased when the content was higher at the case of lower N.After the content of nitrogen was exceeded over 35.8 g·kg^-1,the content of Mg was decreased slightly with the improvement of N.2.Effects on photosynthesis of applying N and MgNet photosynthetic rate was increased for applying N and Mg at appropriate rate.The applying amount of N was 225.0 and 337.5 kg/hm2,then the cooperating application amount of Mg was respectively 112.5,225.0,337.5 kg/hm2,the net photosynthetic rate in booting stage was significantly improved,the increased ratio was 4.3% 29.7%.3.Effects on dynamic of population stems of applying N and MgThe number of harvested ear can be effectively increased for the cooperating application of N and Mg.The applying amount of N was 225,337.5 and 450 kg/ hm2,and the amount of respectively applying Mg was at 225kg/ hm2,the ear number of treatments was increased respectively 15%,10.0% and 14.8% than the un-applied treatment.The ratio of N/Mg and N/（MgK）and the amount of Mg applied were display with the trend of a single curve.The ratio of N/Mg and N/（MgK）could be effectively improved by the apt application of Mg.The content of Mg in leaves during the booting stage was positively correlated with effective tiller rate and tiller spike ratio.The yield could effectively improve with the increase of the N/Mg in nutritional organ..4.Effects on the yield and the yield components of applying N and MgThe results of two-season trial show that the yield was increased for applying singly at the lower content of Mg.The yield was significantly increased with the increasing amount of applied N,but the extent of yield increase was reduced at the excess application of N,and the trend of decreasing yield was even happened.After the cooperated application of N and Mg,N was main factor and the effect of N was larger than Mg.The effect of Mg on yield and interaction of Mg and N was not significant.The yield was evidently improved for the increase of N and Mg in nutritional organ.There was a decreased trend of yield when the content of N and Mg in nutritional organ was excess.Amount of the applied N was positively correlated with ears,spikelet per ear and grain yield,and negatively correlated with seed setting rate and grain weight.The correlation among the amount of Mg and yield component,yield of rice was not significant.The amount of spikelet per ear could be effectively improved by increasing apart the content of N or Mg in leaves at booting stage.The increased extent of yield was different in the treatments with application of N at 337.5kg/hm2 combining application of Mg at 112.5-337.5 kg/hm2.5.Effects on the rice quality of applying N and MgThe N/（Mgk）and N/Mg in grain had no obvious relation with amount of applying N,but obvious relation with amount of applying Mg,applying Mg properly could improve N/（Mgk）and N/Mg efficiently,then the head rice rate improved,too.But when the N/（Mgk）ratio was too high,the head rice rate appears decreasing trend.Two years’ study showed: the chalky rate appeared significant negative correlation with the head rice rate.After applying N and Mg together,N had significantly influence on the chalky rate,Mg’s influence on the chalky rate and the head rice rate both reach a clearly high level during the two yeas’ tests.High level of N combined with applying 228.0kg³37.5kg Mg every hectare decreased the rice’s chalky rate obviously,but improved the head rice rate.Applying fertilizer singly,the taste quality will improved at first,then decrease as applying Mg more and more,no matter low or high amount Mg was,the taste quality will decrease.When applying N singly,low amount of N improved taste quality;high amount of N decrease taste quality obviously,two years’ study showed: dealing with high amount of N combined with low amount of Mg can sincerely improved the taste.Dealing with applying 337,8kgN+112.8kg Mg each hectare and applying 480.0kg N+ 112.5kg Mg each hectare both had less obvious and effective influence on taste quality than dealing with applying Mg,improving separately 0.2% and 2.3% in 2009;3.8% and 1.4% in 2010 6.Effect on yield of whole milled rice yield applying N and MgYield of whole milled rice was one of the comprehensive evaluation indexes on the yield and the quality of rice.The results of two-season trial showed that there was a positively correlation among the ear per unit area,the spikelet per ear in the yield component,and yield of whole milled rice,there was negatively correlation between rate of seed setting and whole milled rice.When the Mg was applied singly,the yield of whole milled rice was decreased at the lower amount of Mg.The effect on improved yield of whole milled rice for application of N was significant.After the cooperated application of N and Mg,the effect on the yield of whole milled rice of N,Mg and the interaction of N and Mg was significant.The more applied amount of N was used,the more yield of whole milled rice was higher.There was a gradually decreasing trend when the amount of N was excess.It was adverse for improved yield of whole milled rice applying excess amount of N and Mg.The yield of whole milled rice applying amount of N at 337.5 + Mg at 112.5 kg/hm2 and N at 450.0 + Mg at 112.5 kg/hm2 was higher than the treatment without applying Mg,the increased extent was respectively 1.9% and 5.0% in 2009 and 9.8% and 16.4% in 2010.The results of this study showed that the effect on dry weight of tillering stage and full heading time,dry weight of root in booting stage,the plumpness of basal second internode,carbon and N metabolism,population dynamics and the relation of “resource” and “sink” was significant.The interaction of N and Mg nutrients was complex,the promoting effects and inhibitory effects were simultaneously existed,the difference was existed in various environments too.The interaction of N and Mg was evident at the lower amount of N,but the content of Mg was decreased when the content of N in over-ground nutritional organ was over 35.8g · kg^-1.It indicated that the proportion and balance of N and Mg could be changed at the different applied amount of them.At present,the application of N was more popular than Mg,however it increased the need of Mg due to the application of N,which could induce the efficiency of Mg for the excessive application of N.Therefore,the balance of nutrients uptake by rice could be achieved by promoting rational application of N fertilizer in the field production and regarding the timely supplement of Mg simultaneously,which could actualize the aim of high yield and quality.更多还原