【作者】 张林森；

【导师】 马锋旺；

【作者基本信息】 西北农林科技大学 ， 果树学， 2012， 博士

【摘要】 春季土壤干旱、土壤有效养分含量低以及肥水缺乏相互协调是黄土高原优质苹果生产中的关键问题。因此研究优质苹果生产中水分养分的吸收规律、耦合作用及其管理技术，可为提高果实产量和品质提供技术支撑。本研究通过多年多点调查分析陕西渭北优质苹果园土壤养分状况，建立了分级指标体系，开展了土壤注射施钾试验，为苹果园制定合理施肥方案提供了基础数据。通过多年研究苹果园树体长期分区干旱下的树体导水特性、光合、蒸腾、荧光、水分营养、水势等变化规律，及其对苹果产量品质的影响，可为苹果园节水灌溉提供理论依据。同时研究了水钾互作对苹果砧木水力结构影响的生理机理，以期为提高黄土高原苹果园养分水分的利用率和优质苹果生产水肥管理提供一定的指导作用。其主要研究结果如下：1.对陕西渭北8县517个苹果园0～40cm土壤养分状况和97个果园0～120cm土壤剖面养分分布进行了调查分析，并初步开展了土壤施钾或灌溉注射施钾研究。结果表明：渭北苹果产区土壤有机质平均含量为11.35±2.35g.kg-1；铵态氮平均含量为4.67±1.37mg.kg-1，土壤碱解氮为57.08mg.kg-1，土壤有效锌为1.20mg.kg-1，有效锰为12.49mg.kg-1，有效铜为1.46mg.kg-1，有效硼为0.56mg.kg-1，有效铁为12.07mg.kg-1，果园剖面各土层变幅较小。硝态氮平均含量为22.86±24.98mg.kg-1，累积高峰在40～60cm土层深度处，各果园和土层变幅较大，80％左右的测试果园氮含量偏高，并有向下淋溶积累在深层土壤中的趋势。有效磷主要集中在施肥土层0～40cm内，向下淋溶少，磷含量多在标准值以内。土壤有效钾平均含量在177.22mg.kg-1，有效钾变幅较大，钾含量普遍较低。土壤有效钾含量在258～290mg.kg－1以上或土壤施钾600kg/hm2、灌溉施钾375kg/hm2和注射施钾510kg/hm2果实产量品质效果最好，提出旱地苹果园行间覆盖黑膜，膜边缘注射施钾等水肥一体化配套措施是今后旱地优质苹果园高效省力化施肥的方向。2.对黄土高原地区田间条件下全根干旱（NI）、分区灌溉（PRD）与常规灌溉（CI）处理的13年生富士苹果树的的水势、气体交换、叶片和枝条导水等特性进行多年研究。结果表明：富士苹果三个处理的茎水势和叶水势在7月份到达最低值，午后14时的水势值在全天中最小，各月份的茎水势和叶水势大小次序为常规灌溉＞分区灌溉＞全根干旱。随着干旱程度的增加，富士苹果的叶片导水率和枝条导水率逐渐下降，PRD和NI处理的叶片导水率与CI处理相比降低了13.27%和42.01%，PRD和NI处理的枝条导水率与CI处理相比降低了3.01%和34.36%，但是PRD处理的叶比导水率和枝条叶比导水率出现升高，分别比CI与NI处理高出14.32%、14.43%和96.12%、16.55%。与CI和NI处理相比，PRD处理下有更大的叶比导水率，但是其叶片相对含水量RWC介于CI和NI处理之间，可以看出在一定RWC变化范围内，叶比导水率的增加是以牺牲部分叶片相对含水量为代价的。PRD处理的水分利用效率WUE较CI和NI处理显著提高了29.08%和26.82%，其最大净光合效率、表观量子效率和暗呼吸速率介于NI和CI之间。水分亏缺导致了各处理下的叶面积、枝条长度、光合作用等生理指标出现下降。3.分区灌溉在干旱侧土壤水分含量较少时，根系可以通过增加在正常一侧的水分吸收来弥补自身水分的亏缺，并加强对干旱一侧水分的深层吸收。富士苹果0～50mm深度下，根系根毛分布密集，吸收水分相对较多；在50～180cm深度下，根系根毛相对较少，但是对植物吸水起一定作用。长期干旱容易导致苹果果实偏小，可溶性固形物和硬度提高，可滴定酸减少。长期固定分区灌溉，苹果产量容易出现大小年，果品大小分布不匀。ET0/TR0反应中心传递能量与吸收能量的比值在一天中的变化趋势，为双峰曲线，常规灌溉＞全根干旱＞分区灌溉。最大有效光能利用率TRo/ABS和单位反应中心吸收的能量RC/ABS，在一天之中呈现出先减少后增加的趋势，常规灌溉＞分区灌溉＞全根干旱。4.利用高压流速仪（HPFM），研究测定了三种水分和三种钾素水平耦合对平邑甜茶根系、茎杆、叶片、冠层导水率，叶比导水率和茎比导率的影响。结果表明，适度高钾水平下，水分亏缺能够显著降低平邑甜茶根系、叶片、冠层导水率，叶片、冠层的叶比导水率，冠层的茎比导率，在中度水分胁迫和重度水分胁迫下叶片的叶比导水率分别减少为正常灌水条件下的35%和29%。正常灌水时，适度高钾添加能够提高根系、冠层导水率，根系、叶片、冠层的叶比导水率，冠层的茎比导率。适度高钾和过量钾条件下的叶片叶比导水率与低钾的叶片叶比导水率相比分别提高了17%和降低了27%。在严重水分亏缺时，适度高钾条件下气孔导度比低钾条件下气孔导度增28%。水分亏缺和钾素添加处理可以降低平邑甜茶叶片水势，导致栓塞的发生。水分亏缺会导致气孔导度降低，而钾素能在某个水平上降低这种影响；水分亏缺时钾素添加可能通过降低叶片的水势,促进树体木质部栓塞的形成,从而限制水分进一步散失。更多还原

【Abstract】 Soil drought in spring, low in available soil nutrients and incoordination in interactionbetween soil water and nutrition are main problems in high quality apple production inShaanxi apple orchards in the Loess Plateau. Therefore, research on nutrition and wateruptake, interaction and management in high quality apple production can help to improveyield and fruit quality. Soil nutrition status in many Shaanxi apple orchards were analysed inseveral years in present study, classified index of soil available nutrition was established andexperiment of potassium fertilizer with fertigation or soil injection was conducted in order toprovide data base for orchard fertilizer recommendation. Effect of partial rootzone drying onhydraulic conductance, photosynthesis, transpiration, fluorescent properties, water and nutritionuptake, water potential, yield and quality in mature apple trees in field conditions were conductedin several years in order to provide useful information on orchard water-saving irrigation. Thephysiological mechanism of water-potassium coupling on hydraulic conductance on applerootstock was tested, which could be useful in improving soil water and nutrition useefficiency and water and nutrition management in high quality production in apple orchardsin the Loess Plateau. The main results were as follows：1. Soil nutrition status from517apple orchards on0-40cm layer and97soil profiles at0-120cm at8counties in Shaanxi Weibei areas in the Loess Plateau were analyed andsurveyed in several years, and potassium experiments on soil application, fertigation andinjection were conducted preliminary. The result showed that the average content of soilorganic matter were11.35g.kg-1in Weibei apple growing areas, the content of ammoniumnitrogen was4.67±1.37mg.kg-1, alkali nitrogen was57.08mg.kg-1, available zinc was1.20mg.kg-1, available Mn was12.49mg.kg-1, available copper was1.46mg.kg-1, available boronwas0.56mg.kg-1, available iron was12.07mg.kg-1, and didn’t change much in0-120cm soildepth profiles of orchards. The average content of nitrate nitrogen was22.86±24.98mg.kg-1and changed largely, NO3-N accumulating peak was mostly on40-60cm soil layer, soilnitrogen content were slightly high in80%tested orchards, available phosphorus contentwere mostly fitted in the standard range, mainly at0-40cm soil layer of soil application place, average available potassium content was177.22mg.kg-1, and changed largely, were mostlylow in standard. High quality fruit will be produced when soil average available potassiumcontent reach to258-290mg.kg－1, or soil application of600kg/hm2potassim or fertigationwith375kg/hm2or soil injection510kg/hm2potassium with water. Fertigation by soilinjection and black film mulching is the important tenchency of fertilizer application indryland orchards in the near future.2. The effects of whole rootzone drying (NI), partial rootzone drying(PRD), conventionalirrigation(CI), three irrigation modes on the water potential, gas exchange, leaf and shoothydraulic conductivity characteristics in the field conditons of the Loess Plateau were studiedin thirteen years Fuji apple trees orchard. The results indicated that leaf water potential andstem water potential reached the lowest valve in July, diurnal variations of water potentialreached the lowest valve in the14o ’clock, the order of leaf water potential and stem waterpotential in seasonal and diurnal variations were CI＞PRD＞NI. The leaf and shoothydraulic conductance presented a decreasing trend with the increase of drought, leafhydraulic conductance of PRD and NI reduced13.27%and42.01%, shoot hydraulicconductance of PRD and NI reduced3.01%and34.36%compared with that of CI. Butcompared with CI and NI, leaf area specific conductance and shoot area specific conductanceof PRD were enhanced by14.32%and14.43%,96.12%and16.55%, respectively. PRD had abigger leaf area specific conductance compared with CI and NI, however, value of RWC wasbetween the two treatments, it showed that in a certain RWC range, increase of leaf areaspecific conductance were at the cost of decreasing some RWC. Compared with CI and NI,WUE of PRD greatly improved29.08%and26.82%, and its maximum net photosyntheticrate, apparent quantum efficiemty and dark respiration rate were between the CI and NI.Water defict reduced leaf area, shoot length and photosynthetic indexes.3. When soil moisture content on the dry side in half rootzone irrigation was low, appleroots on the irrigated rootzone side increased water uptake to make up for its water deficit andapple roots on the dry side improved water uptake in deeper soil layers. There was more rootsdistribution under0-50mm depths of Fuji apple tree to uptake more water, there was less rootsunder the50-180cm depth, but the trees also had an effect on absorbing water. Longtermdrying easily resulted in smaller apple fruit, higher soluble solids content and flesh firmnes,lower titratable acid. Apple yield presented a trend of biennial fruting and nonuniform fruitsize distribution in half rootzone drying treatment. Ratio of energy transfer and energy absorbin ET0/TR0reaction Center in the course of the day was a bimodal curve, normal irrigation>not irrigation> half root irrigation. Maximum effective light energy utilization of TRo/ABSand RC/ABS units of the reaction Center absorb energy had an tendency with the first decrease and then increase on the day, conventional irrigation> half rootzone drying> wholerootzone drying.4. The effects of water-potassium coupling on hydraulic conductance, leaf area specificconductance, sapwood area specific conductance of root, stem, leaf, plant of Malushupehensis were studied. Three water levels and three potassium levels were set, hydraulicarchitecture of Malus hupehensis were measured with the high pressure flow meter (HPFM).on the high potassium level, water deficit greatly decreased hydraulic conductance of root,leaf and plant, leaf area specific conductance of leaf and plant, sapwood area specificconductance of plant of Malus hupehensis, the leaf area specific conductance of leaf in themoderate and severe water stress reduced to the35%and29%of normal water conditionsrespectively. On the normal irrigation conditions and potassium addition on the high level cangreatly enhanced hydraulic conductance of root and plant; greatly enhanced leaf area specificconductance of root, leaf and plant; also greatly enhanced sapwood area specific conductanceof plant of Malus hupehensis. The leaf area specific conductance of leaf in the high andexcessive high potassium level were increased by17%and lowered27%compared with lowpotassium level respectively. In the severe water deficit, stomatal conductance in the highpotassium level increases by28%compared with low potassium level. Water deficit andpotassium addition treatment decreased leaf water potential and induced xylem embolism.Water deficit reduced stomatial conductance(GS), however, potassium can decreased thisresult on some levels. Potassium addition greatly decreased leaf water potential of the plantssubjected to water deficit, induced xylem embolism and limited water lost further in this way.更多还原