946 resultados para N fertilization
Resumo:
本文以吉林省公主岭“国家黑土肥力与肥料效益长期定位监测基地”的黑土为材料,研究长期施肥对黑土POM的分布及POM(FPOM和OPOM)中碳水化合物特性的影响,结果表明: 有机肥及有机肥与化肥配施显著提高了土壤中碳水化合物的含量,促进了植物来源的中性糖和真菌来源的氨基糖在土壤中的积累。在有机质含量较高的黑土上长期施用高量有机肥会出现养分过剩的现象。不同施肥处理下黑土有机质中中性糖的相对含量与不施肥相比无显著变化,氨基糖的相对含量则显著增加。随着有机肥施用量的增加,土壤中中性糖的含量也随之显著增加,而氨基糖则没有明显变化。 有机肥及有机肥与化肥配施能显著增加黑土中POM以及POM-C、POM-N和碳水化合物的含量,且均随有机肥施用量的增加而增加。各个处理中OPOM的碳、氮和碳水化合物含量远远高于FPOM。POM中各个单糖对施肥的响应与碳水化合物的总量基本一致。单施高量有机肥及有机肥与化肥配施均能显著提高POM中中性糖和氨基糖占有机质的比例,单施低量有机肥对POM中氨基糖和FPOM中中性糖占有机质的比例作用不明显,而能显著增加OPOM中中性糖占SOM的比例。在POM的中性糖中葡萄糖和木糖对SOM的贡献较大,氨基糖中氨基葡萄糖的贡献较大。OPOM中碳水化合物对SOM的贡献大于FPOM。FPOM中中性糖主要来源于植物,而OPOM中则主要来源于植物和微生物。在短期范围内,施肥并没有引起POM中两种来源氨基糖比例的显著变化,而从长期来看,有机肥处理却使POM中细菌源氨基糖的积累得到了加强。单施化肥对黑土有机质和黑土POM的含量以及二者中的碳、氮和碳水化合物的含量和组成均没有显著的影响。
Resumo:
大气CO2浓度升高能够对农田生态系统产生一系列的影响。土壤线虫在农田生态系统腐屑食物网中占有重要的地位,能够对外界环境变化作出较迅速的响应。本文利用江苏省江都市小记镇的稻-麦轮作FACE系统研究平台,在2007-2008年小麦生长季,研究了大气CO2浓度升高和不同氮肥处理(高N和低N)对农田土壤线虫群落的影响。 研究结果表明:高氮肥施用情况下, CO2浓度升高显著降低了麦田土壤铵态氮和硝态氮含量。不同氮肥处理中CO2浓度升高条件下土壤可溶性碳的含量显著低于对照,而土壤总有机碳和微生物量碳含量高于对照。 大气CO2浓度升高条件下,麦田土壤线虫群落组成和多样性与对照相比表现出显著差异。CO2浓度升高显著增加了麦田土壤线虫总数、食细菌线虫、食真菌线虫和植物寄生线虫数量。在小麦拔节期和成熟期,低N和高N施用条件下,FACE处理中土壤线虫多样性指数(H’)、成熟度指数(MI和PPI)均低于对照处理,而结构指数(SI)高于对照处理。线虫生态指数的结果表明,大气CO2浓度升高条件下,土壤线虫群落多样性降低,土壤环境受到一定的干扰,食物网趋于结构化。
Resumo:
本文研究施化肥和海洋微生物制剂对桉树人工林土壤质量的影响。研究结果表明:施用不同的化肥对桉树人工林土壤质量影响具有明显差异;从海洋植物根际分离得到的微生物菌株制成的微生物制剂中的活性微生物菌株能够在桉树人工林土壤中定殖,对桉树生长具有一定促进作用。桉树凋落叶分解过程中是否释放化感物质是桉树人工林发展过程中人们普遍关注的问题之一,本论文也对该部分做了初步研究。 对施用长效尿素、芬兰复合肥、高峰复合肥三种不同化肥对桉树人工林土壤质量的的影响进行了初步研究,研究结果表明长效尿素在保障土壤氮素供应、促进土壤纤维素分离能力提高和增强土壤对磷元素吸收方面具有重要作用;芬兰复合肥在增强土壤呼吸作用和促进土壤酶活性提高方面优于长效尿素和高峰复合肥。 以两株海洋来源的枯草芽孢杆菌(Bacillus subtilis 3512, Bacillus subtilis 3728)和一株海洋木霉(Trichoderma TF4)为研究材料,在实验室条件下对其生防机理进行了研究,研究表明:两株枯草芽孢杆菌通过产生脂肽和蛋白酶对植物病原菌产生抑制作用;海洋木霉TF4则能够产生HCN,IAA类植物生长激素,同时还具有一定的解磷能力,具有很好的应用前途,采用传统分类学方法和分子系统学方法鉴定为棘孢木霉(T.asperellum)。这三株海洋菌株制成微生物菌剂,在原位条件和盆栽条件下考察了其对桉树生物量和土壤质量指标的影响,研究结果表明将三株海洋微生物混合后添加少量三叶草作辅剂,能有效改善桉树人工林土壤质量,并促进桉树树高和胸径的增加,具备进一步研究和开发成产品的价值。 用高效液相色谱(HPLC)对桉树凋落叶中毒性物质进行分离、纯化,以小麦、绿豆、大速生菜为指示植物,对分离到的物质进行毒性跟踪,分离到一个毒性较强的组分,经1H氢谱和NMR鉴定为3–β甲酰基–乌索酸。
Resumo:
本研究以潮棕壤一组进行了18年的长期定位试验(开始于1990年)为平台,以室内分析为主要手段,研究不同施肥制度下农田生态系统Fe、Mn、Zn、Cu、Pb5种微量元素的分布及转化情况。该长期定位试验涵盖了中国颇具代表性的八种施肥模式,此处选择其中的四种施肥模式:不施肥(CK)、单施循环猪圈肥(M)、施氮磷钾化肥(NPK)和氮磷钾化肥与循环猪圈肥配施(NPK+M)。结果表明: 施肥对土壤全量微量元素浓度没有显著影响,但对有效态的浓度影响显著,施肥导致土壤有效态微量元素浓度增加,具体表现为NPK+M处理微量元素有效态最高,NPK处理次之,M处理更低,CK处理最低。 不同施肥处理下不同作物中微量元素浓度变化各异,但多由作物产量的变化而引起,玉米籽实和秸秆及大豆籽实中Mn浓度随产量的升高而升高,大豆籽实中Fe浓度也随产量的升高而升高,玉米秸秆中Zn浓度和大豆秸秆中Cu浓度均随着产量的增加而降低。年际间作物体内Fe、Zn、Cu浓度相对稳定,Mn的浓度出现波动。大豆籽实中所测微量元素浓度均显著高于玉米籽实中对应元素浓度,较玉米具有更高的营养价值。 不同施肥处理间作物收获物中微量元素含量有极显著差异,表现为:NPK+M>NPK>M>CK。且作物收获物中微量元素的含量与作物籽实产量(或秸秆产量)间有极显著的相关关系。不同作物收获物中微量元素的分配也不相同,玉米收获物中微量元素主要分配在秸秆中,而大豆主要分配在籽实中。 有机肥和化肥均可向农田生态系统输入微量元素,其中以有机肥形式输入农田的微量元素远大于以化肥形式输入的量,且微量元素的输入量随有机肥用量的增加而增加。 不同元素在饲喂-堆腐过程中的循环率差异较大,Zn的循环率最低,但也能超过70%,而Fe、Mn、Cu、Pb的循环率均可超过80%,其中Fe、Mn、Pb的循环率均接近90%,且微量元素的循环率随着投料量的增加有增加的趋势。 各处理土壤微量元素收入均小于支出,不同处理间收支差额NPK+M<M<CK<NPK,单施化肥加剧土壤微量元素赤字化,养分循环利用可弥补土壤微量元素的损失,减小收支差额。
Resumo:
有机磷是植物和微生物的重要磷源,其各化合物含量组成在一定程度上可反映土壤供磷情况。31P 核磁共振谱仪(31P NMR)通过监测核磁共振频率可以将有机磷不同组分加以区分,是测定土壤有机磷组分的理想工具。本文以吉林省公主岭市不同施肥处理(不施肥处理Control;无机肥处理NPK;有机肥处理M1 、M2;有机无机配施处理M1+NPK、M2+NPK)的长期试验地典型黑土为研究对象,对其有机磷组分应用31P NMR技术进行了研究。结果发现: 1、上机样品的浓度对谱图的影响大,同一批样品需按照同一方法配制,且浓度不是越高越好。冻干前浸提液不中和,试验中未发现磷酸二酯,土壤的NaOH-EDTA浸提液在冷冻干燥前中和,可以减少磷酸二酯的水解;土壤全碳对实验谱图的分辨率有较大的影响。 2、Control处理和NPK处理磷酸单酯含量占浸提液全磷量的比例最高,分别为41%和38%,M2 + NPK处理比例最低为13% 。肌醇六磷酸盐含量占总有机磷量的比例在7% ~ 28%之间,Control处理最高,显著高于NPK处理、M1处理、M1 + NPK处理和M2 + NPK处理。土壤焦磷酸盐含量占浸提液全磷含量比例为0.01% ~ 0.31%,施有机肥处理土壤焦磷酸盐含量显著高于Control处理和NPK处理。 3、土壤浸提液冷冻干燥前中和,测定结果均发现胞壁酸(属磷酸二酯)的峰,中和后的测定磷酸二酯含量占浸提液全磷量的比例在0.53%和3.75%之间;且在Control处理发现-5.28ppm、-26.19ppm和-27.54ppm处发现三个未知峰;Control处理未知化合物占总有机磷的比例为0.35%。
Resumo:
文冠果(Xanthoceras sorbifolia Bunge)是我国北方特有的木本油料树种,已被列为生物质能源树种之一。现阶段产量低是限制其发展的重要因素。本文以内蒙古赤峰市翁牛特旗文冠果经济林场内50年生文冠果树为研究对象,对文冠果生物学、生态学特性进行定位观测和试验,分析了文冠果发育节律与积温的关系。野外布置水肥措施试验,测定了文冠果产量和叶片、果实养分元素(N、P、K、Mg、Ca、Fe、Zn、Cu、Mn)的含量,分析了水肥措施对叶片、果实养分分配的影响。 主要结论: 1.文冠果物候期与积温呈显著的直线函数关系。能够用来预测文冠果年生长发育期有效积温的理论值,为经营管理提供依据。 2.文冠果叶片中主要元素含量随物候期的变化呈下降趋势,但微量元素呈增加趋势。养分重吸收水平由大到小的顺序是:Mg>N>K>P,一定的水肥措施提高了文冠果养分再吸收水平,并降低了功能叶中的N/P、C/N。 3.文冠果果实中Ca和Fe随物候期的变化呈下降趋势,其他元素呈先减后增趋势。水肥措施降低了果实对养分元素的分配和收获系数;提高了养分利用效率。 4.合理的水肥措施能显著提高种子产量,增加含油率。最佳水肥措施为:5月初灌水50mm,施肥量为N 63 g•株-1、P2O5 83.3 g•株-1,于5、7月初分2次等量施入。 5.水分、P是文冠果生长的主要限制性因子,限制性因子具有阶段性。水分对肥效有“激发效应”。
Resumo:
在辽西一缺磷的碳酸盐褐色土上的九年试验结果表明:试验地土壤的年自然供磷能力约为9Kg.P/ha,其中90%自耕层土壤。历史上通过施用农家肥建立起的低水平土壤活性磷库的供磷能力十分有限,在不施磷肥情况下只能提供作物吸磷的12%。每年施用磷肥14Kg.P/ha,九年间作物持续丰产甚至高产,每年小剂量施磷方式的作物增产效果略优于六年一次大剂量施磷方式。土壤中残留肥料磷进入活性磷库的比例均以每年小剂量处理较高。试验地土壤的无机磷库以Ca-P为主,Ca_2-P、Ca_8-P、Fe-P、Al-P均是作物的有效磷源,其中以Ca_2P的活性最高。施磷能普遍提高各有效磷源的含量。有机--无机相结合的施肥处理,九年间获得了最高的作物产量,土壤活性磷、速效磷和各有效磷源的增长也最为显著。
Resumo:
本文通过一组中期肥料试验研究分析了几种施肥制度对辽宁西部半干旱区褐土理化性状的影响,结果表明:通过物质循环再利用是保持土壤肥力的有效措施,它可使土壤有机质、全氮、全磷和速效磷含量显著提高。连续11年的作物产量表明,有机无机相结合施肥制度下该系统不但获得了最高的作物产量,而且产量受外界影响最小,系统稳定性最好。无机农业施肥制度的不同投磷方式对土壤理化性状有一定的影响,其作用是相近的,与无磷处理相比土壤结构和水分特性表现出改善的趋势。综上所述,有机无机相结合施肥制度对辽西半干旱地区建立适合该地农田生态系统良性循环的优化经营模式,不断改善土壤生态环境,促进农业生产持续发展,有重要的理论和实践意义。
Resumo:
人类向大气中排放的大量氮氧化合物和氟氯烃类化合物(CFC’s)引起臭氧分子的分解,导致到达地球表面的紫外辐射增加,特别是UV-B辐射增强。本项目以青杨组杨树为模式植物,从形态和生理方面研究了来自不同UV-B背景下的康定杨与青杨在增强UV-B下的反应及其反应差异,并探讨了干旱、施肥对它们抗UV-B能力的影响。杨树具有分布广、适应性强、在生态环境治理和解决木材短缺方面均占有重要位置,研究成果可为生态系统的恢复与重建提供理论依据和科学指导。主要研究结果有以下: 1. 在温室中经过增强UV-B处理,杨树的外部形态及生理活动受到了一定程度的影响。增强UV-B导致康定杨、青杨的生物量、叶面积及节间长度降低,叶片增厚,SOD活性升高,膜伤害增加,而对叶片数目、R/S、叶绿素A、叶绿素B及整个叶绿素含量没有影响。两种杨树对UV-B胁迫的响应存在差异:在增强UV-B条件下,青杨的植株高度、生物量、叶面积、脯氨酸含量、长期用水效率受到的影响大于康定杨,相比而言,康定杨在比叶面积、叶片厚度、可溶性糖含量、UV-B吸收物质的含量及SOD和GPX活性方面增加的程度大于青杨。这些区别说明,来自于高海拔的康定杨比来自于低海拔的青杨对增强UV-B 具有更强的耐性。我们认为二者在叶片厚度、比叶面积、UV-B吸收物质含量及SOD、GPX活性差异是导致对增强UV-B耐性不同的原因。 2. 干旱与增强UV-B对杨树的生长和生理特性均产生了影响,而且两种胁迫共同作用时干旱表现减弱或加剧了UV-B对杨树某些形态和生理特性的影响。 据试验结果,干旱显著地降低了杨树的株高、叶片数目、叶面积,增加了叶片厚度,促进ABA的积累,提高了CAT活性。对于干旱,两种杨树之间也表现出了一定的差异性。可溶性蛋白质和脯氨酸在青杨叶片中得到显著积累,而在康定杨中没有变化。此外,CAT、长期用水效率在康定杨中受到的影响更加明显。长期用水效率的不同变化趋势说明两种杨树对水分胁迫采用了不同的用水策略,康定杨采用的是节水用水策略,提高用水效率,而青杨采用的是耗水的用水策略。根据干旱对叶面积、脯氨酸、ABA含量、CAT活性及长期用水效率等方面的影响,我们认为来自高海拔地区的康定杨比来自低海拔的青杨有更大的耐旱性,这是对生长环境长期适应的结果。在高海拔地区,因霜冻常带来土壤水分不可利用,降低了根系对水分的吸收,树木容易受到的生理性干旱。另外,高海拔的地区低的气温使植株对严寒有较强的耐性,减少了水分的需要。 生长于增强UV-B下的康定杨和青杨植株表现为高度降低,叶面积缩小,比叶面积增加;叶片栅栏组织、海绵组织均受到增强UV-B的影响,其厚度的增加导致整个叶片变厚。增强UV-B还显著提高了杨树的APX活性、UV-B吸收物质含量,而对叶片数目、ABA、可溶性蛋白质含量及CAT活性没有产生影响。试验中也观察到了两种杨树对增强UV-B响应的差异:与康定杨相比,在增强UV-B下青杨株高、叶面积降低的程度更大一些,SOD活性显著提高。另外UV-B吸收物质受到的影响不同。根据这些差别,高海拔的康定杨(3500 m)比来自低海拔的青杨(1500 m)增强UV-B有较强的耐性。 与水分充足情况下UV-B对植株的影响相比,干旱对杨树抗增强UV-B产生了一定的影响,表现为加剧或减弱UV-B对植物的影响,但这种影响与形态、生理指标有关。当干旱与增强UV-B共同作用时,杨树植株的株高、叶面积进一步降低、叶片进一步增厚。就脯氨酸的积累的而言,在没有水分胁迫时,增强UV-B促使它显著增加,而在干旱处理下这种效果变得不明显。干旱对增强UV-B的影响还与杨树的种类有一定的关系。在康定杨中,干旱减弱了增强UV-B对栅栏组织与海绵组织的影响,且在植株高度、叶面积上表现出累加效应,而在CAT上交互作用显著;但在青杨中干旱则加剧增强UV-B对栅栏组织与海绵组织的影响,在植株高度、叶面积及比叶面积上表现出显著的交互作用。据碳同素分析,在水分充足的条件下,无论是康定杨,还是青杨,增强UV-B均导致其长期用水效率的提高,然而当两种胁迫共同作用时,长期用水效率则表现出差异,在青杨中,长期用水效率得到进一步增高,而康定杨中干旱的效应被增强UV-B所减轻。 3. 田间试验表明,杨树的生长、生理特征都受到养分和增强UV-B的影响。施肥对杨树的影响表现为:提高了叶面积、生物量及SOD的活性,降低了抗坏血酸含量。对于施肥作用,两种杨树的反应也有区别:在康定杨中施肥显著增加了的叶片长度、宽度及光合色素的含量,降低了净光合速率、气孔导度及胞间CO2浓度;在青杨中,则SOD、GPX、APX活性表现增加。从试验看出,施肥对来自于高海拔地区的康定杨(3500 m)的影响较大,对来自低海拔的青杨(1500 m)影响较小,这与它们对原产地的生境适应有一定关系。在康定杨生长的高海拔地区,低温度和湿度不能为地上凋落物或土壤中的根分解提供理想的条件,造成当地土壤的低养分状况,所以当肥料施用以后,效果显著。 经过增强UV-B处理,杨树叶片中UV-B吸收物质含量、GPX的活性得到提高,而脯氨酸、丙二醛、可溶性蛋白质、叶绿素及类胡萝卜素含量没有受到影响。对于增强UV-B两种杨树受到的影响也有所不同:在青杨中增强UV-B导致叶面积缩小,生物量、净光合速率降低,APX的活性及长期用水效率的提高,而对康定杨的这些指标没有产生显著影响,相反抗氧化酶的活性明显高于青杨。这些差异性是由于两种杨树对原产地不同UV-B背景的长期适应结果。康定杨长期生长在较高UV-B环境中,对UV-B有较强的耐性。而青杨适应于较低的UV-B环境,对增强UV-B较为敏感。 试验中施肥也影响了植株对增强UV-B的反应,不过这种影响与杨树的种类及测定指标有一定的相关性。例如,在缺肥的情况下,青杨的长期用水效率和康定杨的叶绿素含量都受到增强UV-B的显著影响,而施肥以后这种影响变得不显著。在缺肥的条件下,GPX、APX在青杨中的活性、GPX在康定杨中的活性对增加UV-B反应不敏感;而施肥以后则变化显著,同样胞间CO2浓度在康定杨也有类似的变化。 For past decades, Ultraviolet radiation, especially UV-B reaching the Earth’s surface increased because of depletion of ozone layer resulted from emission of NxO and CFC’s from human activities. In this experiment, different species of Populus section Tacamahaca Spach from different UV-B background were selected as a model plant to assess the effects of enhanced UV-B radiation. Morphological and physiological traits induced by enhanced UV-B were observed and the different responses between P. kangdingensis and P. cathayana were discussed, furthermore the influences of drought and fertilizer on responses induced by enhanced UV-B were studied. Since poplars play an important role in lumber supply, and are important component of ecosystems due to their fast growth and wide adaptation, the study could provide a strong theoretical evidence and scientific direction for the afforestation, and rehabilitation of ecosystem. The results are as follows: 1. The experiment conducted in a greenhouse indicated that morphological and physiological traits of two poplars were affected by enhanced UV-B radiation. Enhanced UV-B radiation not only reduced biomass, leave area and internode length, but also increased leaf thickness and SOD activity as well as MDA concentration and electrolyte rate. However, no significant changes in leaf numbers, root shoot ratio, and total chlorophyll and chlorophyll component were observed. There were different responses to enhanced UV-B radiation between two species. Compared with P. kangdingensis, cuttings of P. cathayana, exhibited lower height increment and smaller leaf area. In addition, there were significant differences in free proline, soluble protein, and UV-B absorbing compounds, and the activity of SOD and GPX, long-term WUE between them. Differences in plant height, biomass, leaf area, free proline concentration, and long-termed WUE showed that P. cathayana were more affected by enhanced UV-B radiation than P. kangdingensis. In contrast, more increase of specific leaf mass, leaf thickness, and soluble sugar, and UV-B absorbing compounds, and activity of SOD and GPX were observed in P. kangdingensis. According to these results, we suggested that P. kangdingensis from high elevation, which adapted to higher UV-B environments, had more tolerance to enhanced UV-B than P. cathayana from low elevation, which adapted to lower UV-B environment. We believe it was the difference of leaf thickness, specific leaf mass, and UV-B absorbing compounds as well as the activity of SOD and GPX resulted in lower adaptation of P. cathayana to enhanced UV-B radiation. 2. Growth and physiological traits of two poplars were affected by both drought and enhanced UV-B radiation. Moreover, it was observed that when two stresses applied together drought could exacerbate UV-B effects or decrease sensitivity to UV-B. In the experiment, drought significantly decreased plant height, leaf numbers, leaf area, and increased leaf thickness, and ABA, and CAT activity of two poplars. There were significant interspecific differences to drought stress. Exposed to drought, soluble protein and proline concentration were increased in P. cathayana but not in P. kangdingensis. However, more changes in CAT and long-term WUE were observed in kangdingensis. Different change in long-term WUE suggests that two poplars adapted different water-use strategies. P. kangdingensis employ a conservative water-use strategy, whereas P. cathayana employ a prodigal water-use strategy. Based on the differences in leaf area, accumulation of free proline and ABA, CAT activity as well as long-term WUE, we believed that P. kangdingensis from high elevation had a greater tolerance to drought than P. cathayana from low elevation,which is the result of adaptation to local environment. In high elevation area, trees are prone to suffer from physiological drought because of un-movable water caused by frost. Besides lower temperature enable the plants had greater adaptability to frost as a results the requirement of water is reduced Enhanced UV-B radiation decreased shoots height, leaf area, and increased specific leaf mass and thickness of palisade and sponge layer as well as APX activity and UV-B absorbing compounds in both species. Whereas, leaf numbers, ABA content, soluble protein and CAT activity showed no differences to enhanced UV-B radiation. Interspecific differences were also observed. Compared with P. kangdingensis, P. cathayana showed lower shoot height and smaller leaf area, higher SOD activity. Besides, variation in UV-B absorbing compounds was found. These differences suggested that P. kangdingensis from high elevation (3500 m) was more tolerant to enhanced UV-B radiation than P. cathayana from low elevation (1500 m). Compared with morphological and physiological changes induced by enhanced UV-B radiation under well-watered conditions, drought exacerbated or decreased these changes. However, these effects vary with parameters measured. When two stresses applied together, shoot height and leaf area further decreased while leaf thickness further increased. Under well-watered conditions, enhanced UV-B radiation significantly increased proline content, but such effect was not observed under drought conditions. The effect of drought on enhanced UV-B radiation was related to species. For example, drought reduced the effects of enhanced UV-B radiation on palisade parenchyma and sponge mesophyll in P. kangdingensis, and additive effects in shoot height and leaf area and interactive effect CAT activity were observed. In contrast, for P. cathayana drought significantly exacerbated the effects of enhanced UV-B radiation on palisade parenchyma and sponge mesophyll; there were noticeable interaction in shoot height, leaf area and specific leaf mass. As far as long-term WUE is concerned, it was increased by enhanced UV-B radiation under well-watered conditions in both species. While different effect was observed between two species in combination of two stresses. Long-term water use efficiency was further increased in P. cathayana whereas the effect was less significant in P. kangdingensis. 3. The field experiment showed that growth and physiological traits of poplars were affected by nutrition and enhanced UV-B radiation. Fertilization significantly increased leaf area, biomass and SOD activity, reduced Ascorbic acid concentration. There was interspecific difference in response to fertilization. For P. kangdingensis, fertilization significantly increased leaf width, leaf length and photosynthetic pigments content while net photosynthetic rate and stomatal conductance, intercellular CO2 concentration were significantly decreased. However, for P. cathayana, these parameters were unaffected except the increase of SOD, GPX and APX activity. From above, it could concluded that P. kangdingensis from high elevation was more affected by fertilization than P. cathayana, This difference was due to adaptation to local environment., The low temperature and moisture where P. kangdingensis was collected can not provided optimum to decompose roots and litter fall as a result the nutrition in soil was poor. Exposed to enhanced UV-B radiation, for both species UV-B absorbing compounds and GPX activity were significantly increased while proline, MDA, soluble protein, chlorophyll, carotenoids were not affected. Different responses were also observed between the two species. Enhanced UV-B radiation caused significant decreases in leaf area, biomass, net photosynthetic rate and increase in APX activity and long-term WUE in P. cathayana but not in P. kangdingensis. In addition, activity in antioxidant enzymes was much higher in P. kangdingensis than in P. cathayana. In the experiment fertilization affected responses of cuttings to enhanced UV-B radiation, but it concern species and parameters measured. Long-term WUE in P. cathayana and chlorophyll in P. kangdingensis were significantly increased by enhanced UV-B radiation under non-fertilization treatments while the increase was not found under fertilization treatment. In contrast, under no fertilization treatment enhanced UV-B radiation did not affected GPX and APX activity in P. cathayana and GPX in P. kangdingensis while significant increase appeared after application of fertilization. Similar effect of enhanced UV-B radiation on intercellular CO2 concentration in P. kangdingensis was observed.
Resumo:
人类活动引起全球大气中温室气体(CO2、CH4、NOx)浓度不断增加,致使地球表面温度在过去的100 年中已经增长了0.74 ± 0.18℃,预计到本世纪末将会增加1.1-6.4℃。此外,氮沉降也是当今社会的重要环境问题,随着经济发展的全球化, 高氮沉降也呈现出全球化趋势。全球气候变暖和氮沉降给陆地生态系统的地上、地下生物学和生物地球化学过程所带来巨大影响越来越引起人们的关注。 本文以川西亚高山针叶林的两个重要树种云杉和油松幼苗为研究对象,采用红外辐射增温(空气增温2.1℃,土壤增温2.6℃)和根部施氮(施氮量25 g N m-2yr-1)的方法,从生长形态、光合作用、抗氧化能力和矿质营养等方面研究这两种幼苗对气候变暖和氮沉降的响应。该实验为室外控制实验,包括四个处理:(1)不增温+不施氮(UU);(2) 不增温+施氮(UF);(3) 增温+不施氮(WU);(4) 增温+施氮(WF)。本研究旨在从生理生化、物质代谢 、生长及形态等不同水平上研究模拟增温和施氮对两种树苗的联合效应,提高我们对全球变化下亚高山针叶林早期更新过程的理解,同时也为森林管理提供科学依据。具体研究结果如下: 单独增温处理显著提高了云杉和油松幼苗的地茎、叶重、茎重、根重以及总生物量;单独施氮处理也增加了两种幼苗的株高和总生物量。而增温和施氮联合作用对两种幼苗生长的影响并不相同,联合作用对云杉幼苗生长指标的正效应显著低于单独施氮处理,但是联合作用比单独增温或施氮更大程度的促进了油松幼苗生物量的积累。 单独增温和施氮都有利于提高云杉和油松叶片中叶绿素含量、净光合速率(A)、最大净光合速率(Amax)、表观量子效率(Φ)、最大光能转化效率(Fv/Fm)和量子产量(Y)。与对两种幼苗生长指标的影响相似,加氮和增温共同作用下油松幼苗的以上光合指标比在单独增温或施氮处理下有更大程度的提高;而联合作用下云杉幼苗叶绿素含量、净光合速率、最大净光合速率、表观量子效率、最大光能转化效率以及量子产量比单独施氮处理明显地降低。 增温和施氮都显著地降低了云杉和油松幼苗针叶组织中活性氧和丙二醛的积累。交互作用降低了云杉幼苗叶片的抗氧化酶活性、脯氨酸和ASA 的含量,却显著提高了油松幼苗SOD、POD、APX 等抗氧化酶的活性,并且对油松幼苗脯氨酸和ASA 积累的促进作用比单一因子更加明显。因此,增温和施氮共同作用下油松幼苗叶片中O2-产生速率、H2O2 及MDA 含量明显降低,而云杉叶片中只有O2-产生速率出现降低趋势。 增温和施氮都降低了云杉体内的P、Ca、Mg 元素的含量,增加了Cu、Zn、Mn 在各器官内的积累。对油松幼苗而言,增温和加氮单独作用也显著降低了Ca 含量增加了Cu、Zn、Mn 的积累,但是不同于云杉幼苗的是P、Mg 也显著增加。增温和施氮联合作用对云杉幼苗体内元素的影响与单一施氮处理或增温处理相似,不同的是比单一因子作用更为明显降低了P、Ca、Mg 含量,增加了植株中N、Cu、Zn、Mn 的含量,但是油松矿质元素含量在联合作用下并没有产生类似于云杉幼苗的双因子叠加效应。 总之,尽管单独增温或者施氮都有利于云杉和油松幼苗生长指标、光合能力以及抗氧化能力的提高。但是,增温和施氮对云杉幼苗生长生理的促进效应非但没有在交互作用下有更大的提高,反而低于单独氮处理。与此不同的是,增温和施氮联合作用比单因子作用更有利于油松幼苗生长及生理指标的提高。 With the continued increase in atmospheric concentrations of greenhouse gases (CO2、CH4、NOx), the mean global surface temperature has increased by about 0.74 ± 0.18℃ over the past century and is predicted to rise by as much as 6.4℃ during this century. Besides global warming, nitrogen deposition is another serious environmental problem caused by human activities, and high nitrogen load has become globalization as a result of global economy development. Global climate warming and nitrogen deposition have induced dramatic alternations in above - and below- ground biology and biogeochemistry process in terrestrial ecosystems, and more and more attention has been invited to those problems. This experiment mainly studies two important species Picea asperata and Pinus tabulaeformis in subalpine coniferous forest of western Sichuan, China. Infared heaters are induced to increase both air and soil temperature by 2.1℃ and 2.6 ℃, respectively. Ammonium nitrate solution (for a total equivalent to 25 g N m-2 year-1) is added to soil surface. There are four treatments in this study: (1) unwarmed unfertilized (UU); (2) unwarmed fertilized (UF); (3) warmed unfertilized (WU); (4) warmed fertilized (WF). This study is conducted to determine the influences of experimental warming and nitrogen fertilization on physiolchemistry, nutrition metabolism, growth and morphology in the two coniferous species seedlings. The current study is favorable for increasing our understanding on the early phase of regeneration behavior in subalpine coniferous forest, and it also provide scientific direction for forest management under future global changes. The results are as follows: Artificial warming alone significantly increased basal diameter, leaf mass, stem mass, root mass and total biomass for Picea asperata and Pinus tabulaeformis seedlings, and single nitrogen fertilization are also favorable for growth of the two species and stimulate plant hight and total biomass. The two species seedlings respond differently to the combination of elevated temperature and nitrogen addition. Warming combined with nitrogen fertilization weakens the positive effects of nitrogen addition for growth of Picea asperata seedlings. However, the combination of elevated temperature and nitrogen fertilization further increase biomass accumulation of Pinus tabulaeformis seedlings. Both elevated temperature alone and nitrogen fertilization alone can increase photosynthetic pigments contents, net photosynthetic rate (A), maximum net photosynthetic rate (Amax), apparent quantity yield (Φ), maximum photochemical efficiency of photosystem II (Fv/Fm) and effective quantum yield (Y). Similarly with growth parameters, the combination of warming and nitrogen addition induced more increment of these above photosynthetic parameters for Pinus tabulaeformis seedlings. However, these photosynthetic parameters of Picea asperata seedlings under the combination of warming and nitrogen addition are lower than those under nitrogen fertilization alone. The levels of active oxygen species (AOS) and malodiadehyde (MDA) in needles of the two coniferous species seedling are obviously decreased by experimental warming or additional nitrogen. Warming combined with nitrogen fertilizer reduces the activities of SOD, CAT and APX, and the contents of proline and ASA of Picea asperata seedlings, but the combination significantly increases activities of these antioxidant enzymes in needlels of Pinus tabulaeformis seedlings and further improves the accumulation of proline and ASA compared to either artificial warming or nitrogen addition. Therefore, the rate of O2 - production, the contents of H2O2 and MDA in needles of Pinus tabulaeformis seedlings are remarkably reduced by the combination of warming and nitrogen addition, but the combination only significantly decreased the rate of O2 - production of Picea asperata seedlings. Elevated temperature or nitrogen fertilization decrease the contents of P, Ca, Mg but increase Cu, Zn, Mn contents for Picea asperata seedlings. For Pinus tabulaeformis seedlings, elevated temperature alone and nitrogen fertilization alone decreased Ca, but increased P, Mg, Cu, Zn, Mn contents. The effects of the combination of warming and nitrogen addition on these element contents in needles of Picea asperata seedlings are added or multiplied the effects of warming and nitrogen addition alone, resulting in less contens of P, Ca, Mg and more contents of Cu, Zn, Mn than either elevated temperature or nitrogen fertilization. Howere, these adding or multipluing single-factor effects on contents of these elements are not observed in the case of Pinus tabulaeformis seedlings. In conclusion, growth parameters, photosynthetic capacities and antioxidant abilities of Picea tasperata and Pinus abulaeformis seedlings are improved by experimental warming or nitrogen fertilization. Interestingly, the positive effects of warming and nitrogen addition on growth and physiological performances are not multiplied by the combination of elevated temperature and nitrogen fertilization, even dempened for Picea asperata seedlings. However, for Pinus tabulaeformis seedlings, growth and physiological performances are further improved by the combination.
Resumo:
采用微波消解、电感耦合高频等离子体原子发射光谱(ICP-AES)的方法,对62份不同小麦品种(系)中锌、铁、铜、钙、钠和钾的含量进行了测定。同时利用红外线品质测定仪对主要品质指标粗蛋白、湿面筋、沉降值进行了测定。结果表明,不同小麦品种(系)中各种矿质元素的含量存在差异,2006年小麦品种中铁含量变幅为18.55-58.19 ug/g,平均为30.83ug/g ,最高与最低的相差39.64ug/g;锌含量变幅为5.70-25.80 ug/g,平均为15.13ug/g ,最高与最低相差20.10ug/g。2008年小麦品种(系)中铁含量变幅为16.68-52.25 ug/g,平均为30.10ug/g,最高与最低相差35.58ug/g;锌含量变幅为12.29-33.47 ug/g,平均为21.11ug/g,最高与最低相差21.18ug/g;钙含量变幅为167.53-348.80ug/g,平均为248.59ug/g,最高与最低相差192.59ug/g;铜含量变幅为2.32-5.83 ug/g,平均为2.98ug/g,最高与最低的相差3.61ug/g;钾含量变幅为1822.71-4414.91 ug/g,平均为2617.87ug/g,最高与最低的相差2634.72ug/g;钠含量变幅为10.25-39.82 ug/g,平均为23.05ug/g,最高与最低的相差29.57ug/g。 两年不同小麦品种(系)中矿质元素的含量分析结果表明:铁、铜、钙、钠和钾含量年际变化不明显,说明小麦对铁、铜、钙、钠和钾的吸收较稳定;锌含量变化较大,可能受环境的影响比较大。分析各矿质元素含量与粗蛋白、湿面筋、沉降值及元素之间的相关关系,结果表明,锌含量与粗蛋白含量呈极显著正相关关系,相关系数为0.317,与湿面筋含量之间呈显著正相关,相关系数达到0.246;铁含量与粗蛋白含量呈显著的正相关关系,相关系数是0.262;铜、钙、钠和钾含量与粗蛋白含量、湿面筋和沉降值之间存在正相关,但不显著,其中钠与沉降值之间为负相关。表明施锌或铁对提高小麦粗蛋白和湿面筋有显著效应,其余矿质元素有促进作用但不明显。 利用RAPD分子标记技术对川育23、41058、川育20及其父母本进行分析,力图从分子水平找到小麦矿质元素含量之间的差异性,琼脂糖电泳结果表明不同的小麦品种(系)间扩增出了差异条带。 以上研究结果,将对筛选“微量营养强化型”小麦新材料,选育“微量营养强化型”小麦新品种奠定基础。 62 different wheat cultivars was digested with HNO3 in a tightly closed vessel heated under micro-wave,then contents of zinc,iron,copper,calcium,sodium and potassium were determined by inductively coupled plasma-atomic emission spectroscopy(ICP-AES).The main indexes of wheat quality such as total protein、wet glu and sedimentation volume were detected by Infratec 1255 Food & Feed Analyzer at the same time.The obtained results showed that variation for all of the mineral elements concentrations among different cultivars were observed .In 2006, the amplitude variation of the iron content was 18.55-58.19 ug/g,the average value was 30.83ug/g,and 39.64ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the zinc content was 5.70-25.8 ug/g,the average value was 15.13ug/g,and 20.10ug/g between the highest-content cultivar and the lowest one.In 2008, the amplitude variation of the iron content was 16.68-52.25 ug/g,the average value was 30.10ug/g,and 35.58ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the zinc content was 12.29-33.47 ug/g,the average value was 21.11ug/g,and 21.18ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the calcium content was 167.53-348.80ug/g,the average value was 248.59ug/g,and 192.59ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the copper content was 2.32-5.83 ug/g,the average value was 2.98ug/g,and 3.61ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the potassium content was 1822.71-4414.91 ug/g,the average value was 2617.87ug/g,and 2634.72ug/g between the highest-content cultivar and the lowest one; the amplitude variation of the sodium content was 10.25-39.82 ug/g,the average value was 23.05ug/g,and 29.57ug/g between the highest-content cultivar and the lowest one. Analysis was made on the annual variation of mineral elements content in different Wheat cultivars ,the result shows:there is no obvious difference of iron ,copper ,sodium、calcium and potassium concentrations in wheat cultivars, suggesting the absorption of the iron, copper, sodium、calcium and potassium by wheat are relatively steady ,but zinc concentrations change obviously ,maybe influenced heavily by environment . The correlation between mineral elements 、mineral elements and total protein、mineral elements and sedimentation volume as well as mineral elements and wet glut were analysed in this paper, the result showed that there was significant positive correlation between zinc content and total protein (the correlation coefficient is 0.317), positive correlation between zinc content and wet glu (the correlation coefficient is 0.246), positive correlation between iron content and total protein (the correlation coefficient is 0.262). there was positive but not obvious correlation between the contents of copper, calcium, sodium or potassium and total protein, wet glut or sedimentation volume,among which was negative correlation between sodium and sedimentation volume.It was indicated zinc or iron fertilization has prominent effects in improving the total protein in wheat, the rest mineral elements have Non- obvious facilitation. The study then forecasted the genetic difference of different wheat by the molecular marker of RAPD in order to find differences in molecular level. Chuanyu23、41058、chuanyu20 as well as their male and female parents were analysed by RAPD markers,Agarose gel electrophoresis of DNA revealed the appearance of differential bands . The above-mentioned results of this study establish the foundation to screening the new materials of wheat of " strengthening type of micro- nutrition ", and to breeding the new wheat cultivars of" strengthening type of micro- nutrition ".
Resumo:
A five-year experiment indicated that the average loss rate of N and P in harvested products through a feeding-composting cycle was about 50% and 15%,respectively.Under high yield condition,the amount of recycled N and P from 80% harvested products and through a feeding-composting cycle in farming systems was about 3751 and 814 kghm~(-2),equivalent to 25%34% of N and 32%56% of P from chemical fertilizers applied each year to the systems.The apparent recoveries of N and P in organic manure increased with the prolongation of fertilization,indicating a synergetic residual effect existed,and was 61% and 39% in average in the five-year experiment.The use of nutrients recycled in the farming systems could not only improve soil fertility,but also increase the recoveries of nutrients and reduce the use of chemical fertilizers.
Resumo:
Iron in seawater is an essential trace metal for phytoplankton that plays an important role in the marine carbon cycle. But most studies focused on oceanic iron fertilization in high nutrient low chlorophyll (HNLC) seawaters. A study of inorganic carbon (IC) forms and its influencing factors was presented in Liaodong Gulf sediments, and especially the influence of iron was discussed in detail. Inorganic carbon in Liaodong Gulf sediments was divided into five forms: NaCl, NH3·H2O, NaOH, NH2OH·HCl and HCl. The concentration of NaCl and NaOH forms were similar and they only occupied the minority of total inorganic carbon (TIC). However, NH3·H2O, NH2OH·HCl and HCl forms were the principal forms of TIC and accounted for more than 80% of TIC. Especially, the percentage of NH3·H2O form was much higher than that in the Changjiang River Estuary and Jiaozhou Bay sediments. All forms of inorganic carbon were influenced by organic carbon,pore water, iron, pH, redox potential(Eh) and sulfur potential(Es) in sediments, moreover, the influences had different characteristics for different IC forms. However, the redox reactions of iron affected mainly active IC forms. Iron had little effect on NH2OH·HCl and HCl forms of IC which were influenced mainly by pH. Iron had a stronger influence on NaCl, NaOH and NH3·H2O forms of IC; the influence of Fe2+ was higher than Fe3+ and its effect on NH3·H2O form was stronger than on NaCl and NaOH forms.
Resumo:
研究了连续25年长期培肥试验条件下土壤脲酶和碱性磷酸酶酶促反应的动力学和热力学特征,从酶学角度揭示长期培肥的效应。结果表明,长期培肥增加了脲酶和碱性磷酸酶酶促反应的Vmax、Vmax/Km和k值;降低了Ea、△G、△H和△S值,说明培肥能提高酶促反应速度、减小活化自由能、加快土壤中物质的生物循环过程。酶促反应动力学参数和热力学参数与土壤性质相关分析表明,酶促反应动力学参数大多依赖于土壤化学性状,基于动力学参数的土壤肥力指标体系可评价土壤肥力水平,且U-Vmax、P-Km、P-Vmax可作为土壤肥力的重要指标。