【作者】 林艳；

【导师】 林开敏；

【作者基本信息】 福建农林大学 ， 森林培育学， 2010， 硕士

【摘要】 桉树(Eucalyptus spp)是我国南方速生丰产林的战略性树种,桉树与杨树、松树一起被称为世界三大速生树种。由于桉树速生丰产、经常效益显著的特性,我国南方各省桉树人工造林的规模不断扩大,因此苗木供不应求的现象也经常发生。加快优质桉树苗木的培育可以有效的缓解这一问题,但目前我国桉树组培容器苗主要采用轻型基质容器育苗方式,而轻型基质保持和释放养分的能力颇低,不能满足苗木迅速生长的需要。因此,苗木生长阶段的营养调控已成为快速培育桉树优质壮苗的一个关键技术。目前在苗木指数生长阶段一般采用经验式的施肥量,并且集中或周期等量地供应,但是这种传统的营养调控技术存在诸多弊端,如营养物添加方式与苗木生长节律不相适应;集中一次性施肥后会造成短期内根介质溶液养分总浓度过高等,将直接地制约苗木生长潜力的最大发挥,降低苗木质量,造成肥料浪费、污染环境等。因此,寻求更为精确的营养调控技术已成为桉树育苗技术体系中急待解决的重要课题。为此,本课题将针对当前桉树育苗存在的各种弊端,应用先进的植物稳态矿质营养理论与技术,深入开展桉树容器苗稳态营养调控技术研究。重点探讨全营养和指数施肥方式(即施肥量相同情况下,在苗木生长阶段,按指数型递增的营养物添加模式补充全营养的养分,使之与苗期生长节律相匹配,尽量保持植物体内养分浓度稳定和平衡,不致像集中或恒量施肥那样,因生物量增加而导致养分稀释)对桉树容器苗的生长特性、根系形态学特性、生物量分配格局、营养吸收及利用效率、根介质环境营养特性和肥料利用率等方面的影响研究;同时对桉树组培容器苗稳态营养调控技术体系中的施肥起始点、施肥周期(或施肥时间长度)以及主要营养元素比例等进行进一步优化研究。本研究目的在于充分挖掘苗木的生长潜力,创造出苗木生长的最高速率,缩短育苗周期,提高苗木质量,并能有效地节约肥料,减少施肥所带来的环境污染,提出一套可快速培育优质苗木的精确营养调控技术体系。这对温室桉树容器工厂化育苗的全新施肥技术体系建立具有重大的现实意义。具体研究结论如下:(1)施肥模式对轻型基质培育的桉树容器苗生长有明显的影响。试验结束时(施肥后第10周),4种施肥模式的桉树苗木苗高、地径、单株生物量和根系生物量基本上均明显高于不施肥(对照),其中尤其以50mg N·株-1全营养指数施肥模式生长效果为最佳。与传统施肥模式相比,50mg N·株-1全营养指数施肥(1#)、25mg N·株-1全营养指数施肥(2#)和50mg N·株-1全营养集中施肥(3#)的3种施肥模式的桉树苗木各生长指标均有明显的增加,这充分说明全营养集中施肥和全营养指数施肥模式对桉树苗木生长的促进作用具有更大的优越性。但从其生长动态和相对生长速率来看,50mg N·株-1全营养集中施肥模式的前期生长较好,而后期生长速率开始下降,显现生长后劲不足的现象,而50mg N·株-1全营养指数施肥和25mg N·株-1全营养指数施肥的苗木生长具有明显的后期优势和持续性。因此,在桉树轻型基质容器育苗的营养调控中,50mg N·株-1全营养指数施肥和25mg N·株-1全营养指数施肥两种施肥模式是较佳的选择。(2)不同施肥模式的桉树苗木苗高、地径、单株生物量和根系生物量动态变化规律总体上呈现出前期4-6周增长较缓慢,而后增长较快的趋势,其动态生长进程符合指数生长模型。在施肥开始后4-6周内,不同施肥模式的桉树苗木各生长指标差异相对较小,而后差异则逐渐拉大,尤其是50mg N·株-1全营养指数施肥与传统施肥模式和不施肥之间。(3)不同施肥模式的桉树容器苗苗木形态特征有一定的差异。试验结束时(施肥后第10周),4种施肥模式的桉树苗木叶片数、主根长及侧根数基本上均高于不施肥,其中叶片数和主根长最大均为25mg N·株-1全营养指数施肥,侧根数最大为50mg N·株-1全营养集中施肥;而4种施肥模式的桉树苗木叶质重则均低于不施肥,其中最小为50mg N·株-1全营养指数施肥,这说明施肥会一定程度地增加苗木叶片数、主根长及侧根数但会明显地降低桉树苗木叶质重,尤其是50mg N·株-1全营养指数施肥和25mg N·株-1全营养指数施肥两种模式。施肥模式对桉树苗木冠根比和叶根比影响不大,但施肥会明显地提高桉树苗木茎根比,尤其是50mg N·株-1全营养指数施肥和50mg N·株-1全营养集中施肥两种模式,这可能与施肥对桉树苗木地上部分生物量(尤其是茎)的促进作用远大于对地下部分有关。(4)试验结束时(施肥后第10周),4种施肥模式的桉树苗木质量指数均明显高于不施肥(对照组),这说明施肥可有效地提高苗木质量。但与传统施肥模式相比,全营养集中施肥和全营养指数施肥模式更有利于提高桉树苗木质量,尤其是50mg N·株-1全营养指数施肥模式,其苗木质量指数为最高。(5)施肥可明显地提高桉树苗木叶绿素a和叶绿素a+b含量,但对苗木叶绿素b和类胡萝卜素含量仅有一定的促进作用。与传统施肥模式相比,全营养指数施肥模式更有利于桉树苗木叶绿素含量的提高,尤其是50mg N·株-1全营养指数施肥,其叶绿素a、叶绿素b、叶绿素a+b和类胡萝卜素含量均为最大。(6)施肥模式对苗木体内各元素含量的影响相对较为复杂,对苗木体内N、P、K元素含量的影响较大,而对苗木体内Ca和Mg元素含量的影响较小;两种全营养指数施肥模式(50mg N·株-1全营养指数施肥模式和25mg N·株-1全营养指数施肥模式)的苗木体内N、P、K元素含量动态变化总体呈现较小波动式的相对平稳趋势,而两种集中施肥模式(50mg N·株-1全营养集中施肥模式和传统施肥模式)则呈现较大波动式的逐渐下降趋势,而且还会表现前期常高于两种全营养指数施肥模式,而后期又低于两种全营养指数施肥模式的现象,尤其是50mg N·株-全营养集中施肥模式。这可能是全营养指数施肥模式的桉树苗木生长具有明显的后期优势和持续性的一个重要原因。(7)施肥模式对苗木体内N、P、K、Ca和Mg元素积累量有明显的影响。与传统施肥模式相比,全营养指数施肥模式和全营养集中施肥更有利于苗木对各营养元素的吸收,从而有效地增加苗木体内N、P、K、Ca和Mg元素积累量,尤其是50mg N·株-1全营养指数施肥。除了50mg N·株-1全营养集中施肥模式N、K和Mg元素积累量后期略有下降外,4种施肥模式的桉树苗木体内N、P、K、Ca和Mg元素积累量动态变化总体上均随时间推移呈现前期缓慢增加,而后期较快增加的趋势,而不施肥则基本上呈现较为缓慢增加的趋势。两种全营养指数施肥模式可较好地保持桉树苗木体内养分比例平衡,其各营养元素的比率与所施入的相应营养液元素比率比较相近,而两种集中施肥模式和不施肥容易造成苗木体内养分比例失调。(8)不同施肥模式的肥料利用率有明显差异。两种全营养指数施肥模式的肥料利用率均不同程度高于两种集中施肥模式和不施肥的,其中以25mgN.株-1全营养指数施肥的肥料利用率为最高。这表明全营养指数施肥模式能更有效地提高肥料利用率。(9)试验结束时(施肥后第10周),施肥模式对轻型基质中N、P、K、Ca和Mg元素含量有一定的影响,其中对K元素含量的影响较大,而对Mg元素含量的影响较小。从施肥前后对比来看,所有施肥模式的轻型基质N元素含量均出现不同程度的下降,P元素含量仅不施肥出现下降,其它施肥模式均出现增加,K元素含量仅传统施肥模式和不施肥出现下降,其它均有所增加,Ca和Mg元素含量则均有不同程度的增加。此外,与其它施肥模式相比,50mg N·株-1全营养指数施肥模式和25mg N·株-1全营养指数施肥模式的轻型基质中各营养元素含量下降或增加幅度相对较小,较好地保持基质中各营养元素含量的相对稳定,而其它施肥模式的下降或增加幅度则相对较大。下降过多可能造成基质养分耗空,不利于肥力维持和苗木后期正常生长,增加过多会造成大量养分残留在基质中,不仅浪费肥料,而且还会可能造成二次抽梢徒长和污染环境。(10)正交试验结果表明,在全营养指数施肥模式中,施N量和施肥起始点对苗高、地径和单株生物量的影响较大,而施肥时间长度则影响不明显。以苗高、地径、单株生物量和苗木质量指数作为评价指标,它们较优组合分别为A1B1C2、A1B1C2、A1B1C1和A1B1C1。(11)应用DRIS营养综合诊断方法,对轻型基质培育桉树容器苗的8个试验处理进行进一步营养诊断分析。营养诊断结果表明,各处理养分的不平衡指标值从高到低的顺序为:5#>3#>4#>试验号3>2#>试验号2>1#>试验号4,这表明5#不施肥处理的养分是最不平衡的。从各处理营养诊断的需肥顺序来看,3#、4#和5#处理对N、K肥料都很缺乏。从总体来看,1#、试验号2、试验号3、试验号4、2#处理各营养元素比例比较平衡,说明了全营养指数施肥模式比较有利植株体内各养分平衡。(12)以苗高、地径、单株生物量和苗木质量指数作为评价指标,对全营养指数施肥模式中主要营养元素比例的正交试验结果表明,除了只有Ca比例对桉树苗高生长的影响较明显外,P、K、Ca、Mg比例对桉树苗木各生长指标的影响基本不明显,这说明本试验在全营养指数施肥模式中,所采用全营养液中主要营养元素比例较为合理。苗高、地径、单株生物量和苗木质量指数对应的较优组合分别为A2B2C2D2、A1B1C2D3、A3B3C3D3和A3B3C2D2。(13)培育基质对桉树容器苗生长有明显的影响,但对于不同生长指标和不同施肥模式会有所不同。在不施肥(对照)和25mg N·株-1全营养指数施肥中,以黄心土为基质培育出的桉树苗苗高和单株生物量均高于轻型基质培育的,而在50mg N·株-1全营养指数施肥中,则是黄心土基质低于轻型基质。在3种施肥模式中,不同培育基质的桉树容器苗地径和苗木质量指数均表现出轻型基质高于黄心土基质。不同培育基质,其最佳施肥模式会有所不同。在以黄心土为培育基质中,25mg N·株-1全营养指数施肥模式为最佳,其桉树苗高、地径、单株生物量和苗木质量指数均最高,并且均表现25mg N·株-1全营养指数施肥模式>50mg N·株-1全营养指数施肥>不施肥(对照);而在以轻型基质为培育基质中,50mg N·株-1全营养指数施肥模式为最佳。其桉树苗高、地径、单株生物量和苗木质量指数均最高。这对今后桉树育苗生产具有重要的实践指导意义。培育基质对桉树苗木N、P、K、Ca、Mg元素含量有明显的影响,其中N、K元素尤为明显。在以黄心土为培育基质中,3种施肥模式中的桉树苗木N含量以25mg N·株-1全营养指数施肥模式为最高,其它的元素含量基本上以50mg N·株-1全营养指数施肥为最高。这与轻型基质有所不同。培育基质对桉树容器苗N、P、K、Ca、Mg元素积累量的影响较大。在以黄心土为培育基质中,3种施肥模式中的桉树苗木N、P、K、Ca、Mg元素积累量均以25mg N·株-1全营养指数施肥模式为最高;而轻型基质则均以50mg N·株-1全营养指数施肥为最高。这与苗木生长指标变化规律相一致。更多还原

【Abstract】 In south China, Eucalyptus (SPP) is the windbreat strategical tree species, Eucalyptus together with poplar and pine trees were called the three fast-growing tree species of world. Due to it’s fast-growing and remarkable benefit characteristic, in south China provinces,the scale of Eucalyptus plantation has been unceasingly expanded, therefore the phenomenon of seedling shortage also often happened. Accelerated the cultivation of qualified Eucalyptus container seedling can effectively relieve the problem, but at present cultivated the container seedlings of Eucalyptus mainly use light matrix, which capacity to keep and releases nutrients is low, cannot satisfy the seedling rapid growth. Therefore, nutrition regulation in seedling growth stages has become a key technology to fast cultivate qualified Eucalyptus seedling. Currently in seedling index growth stage commonly used empirical fertilization, and supplied concentrated or cycle, but this kind of traditional nutrition control technologies exist defects, such as the added nutrients doesn’t fit with seedling growth; After one-time fertilization will cause high root medium total concentration of nutrient solution in short-term, which will directly restricts the potential of seedling growth, lower quality of seedlings, even cause the waste fertilizer, environmental pollution, etc. Therefore, seek more precise nutrition control technology has become an important tesk to be solved in the Eucalyptus seedling technique system.Therefore, the subject will aim at present the existence of Eucalyptus seedling, applicated the advanced plant mineral nutrition steady-state theory and technology, further research the steady-state nutrition regulation technology of Eucalyptus container seedling. Mainly discussed how the total nutrition and way of index fertilization (that is in the same situation of fertilization amount, in seedling stage, according to the exponential increase nutrient add mode supplemented the total nutrition, matched the seedling stage growth rhythms, try to keep nutrient concentration of plant body stable and balanced, not like traditional fertilization made nutrient dilution along with increasing biomass) affect the growth characteristics, root morphology characteristics, biomass allocation pattern, nutrient absorption and utilization efficiency, root medium environment nutrition characteristic, fertilizer use efficiency, etc; meanwhile, for the fertilize starting point, fertilize cycle (or fertilize length) and the main nutrient elements matching made a further optimization study.The purpose of this study is to fully excavate the seedling growth potential and create the highest rate, shorter seedling period, improve seedling quality, and can effectively save fertilization, reduce the environment pollution caused by fertilization, and puts forward a set of precise nutrition control technology system for rapid cultivating high quality seedling. This has important significance to build new fertilize technology system for cultivating Eucalyptus containers seedling by factory nursery in greenhouse. Specific research conclusions are as follows:(1) Fertilization mode has obvious effect to growth of Eucalyptus seedling cultivated in light matrix container. At the end of the experiment (The first 10 weeks after fertilization), the Eucalyptus nursery seedling’s height, ground diameter, biomass and root biomass of 4 kinds application mode, basically were significantly higher than that of no-fertilization (CK), in one particularly the growth of 50mg N per-plant total nutrition index fertilization model was best. Compared with the traditional mode, each growth index in 50mg N per-plant total nutrition index fertilization, 25mg N per-plant total nutrition index fertilization and 50mg N per-plant total nutrition concentrated fertilization these tree fertilization mode were all have a remarkable increased, this fully illustrated that total nutrition concentration fertilization and total nutrient index fertilization greater promoted Eucalyptus seedling growth. But, we can see from its dynamic growth and relative growth rate that 50mg N per-plant total nutrition concentrated fertilization mode growth better on early and later growth rate began to fall, appeared lack of momentum, meanwhile, seedling growth of 50mg N per-plant total nutrition index fertilization and 25mg N per-plant total nutrition index fertilization had obvious superiority and persistent. Therefore, in the nutrition regulation of Eucalyptus container seedling which was cultivated in light matrix, the 50mg N per-plant total nutrition index fertilization and 25mg N per-plant total nutrition index fertilization mode was a better choice.(2) In the mass the dynamic change law of Eucalyptus seedling height, ground diameter, biomass and root biomass in different fertilization mode showed trend that slower growth in the first 4-6 weeks and later rapid growth, the dynamic growth process matched with exponential growth model. After fertilization began in first 4-6 weeks, the difference of each growth index of Eucalyptus seedling among different fertilization mode was relatively small, and then the difference was gradually widened, expecially the difference from the 50mg N per-plant total nutrition index fertilization to the traditional mode and no-fertilization.(3) The seedling morphological characteristics of Eucalyptus container seedling had certain differences among different fertilization mode. At the end of the experiment (The first 10 weeks after fertilization), Eucalyptus seedling leaf number, root length and lateral root number of four fertilization mode basically all higher than that of no-fertilization, in which biggest leaf number and root length both were 50mg N per-plant total nutrition index fertilization, the maximum number of lateral root was 50mg N per-plant total nutrition concentrated fertilization; while the leaf specific weight of four mode were all lower than that of no-fertilization, the minimum was that of 50mg N per-plant total nutrition index fertilization, this showed that fertilization will increase leaf number, root length and lateral root number but obviously reduced the leaf specific weight, especially for 50mg N per-plant total nutrition index fertilization and 25mg N per-plant total nutrition index fertilization these two mode. The effect of fertilization mode to Eucalyptus seedling crown-root ratio and leaf-root ratio was small, but fertilization will significantly improve the shoot-root ratio of Eucalyptus seedling, especially for 50mg N per-plant total nutrition index fertilization and 25mg N per-plant total nutrition index fertilization these two mode too. This may be related to fertilization had a large improvement on aboveground biomass of Eucalyptus seedlings (especially stems) than that of the underground.(4) At the end of the experiment (The first 10 weeks after fertilization), Eucalyptus seedling quality index of four fertilization mode were significantly higher than that of no-fertilizer (CK), which indicated that fertilization can effectively improve the quality of nursery stock. But compared with the traditional fertilization mode, the total nutrition concentration fertilization mode and total nutrition index fertilization mode could much more improve the quality of nursery stock, particularly the 50mg N per-plant total nutrition index fertilization.(5) Fertilization could obviously improve Eucalyptus seedling chlorophyll-a and chlorophyll-(a + b) content, but only had a certain stimulative effect to its chlorophyll-b and carotene content. Compared with the traditional fertilization mode,the total nutrition index fertilization mode was more advantageous to increase Eucalyptus seedling chlorophyll content, especially 50mg N per-plant total nutrition index fertilization which chlorophyll-a, chlorophyll b, chlorophyll-(a + b) and carotenoids content were all most.(6) The effect of fertilization mode to the content of each element in seedling was relatively complicated, had great impact on N, P, K elements content of seedling but small on Ca,Mg elements content; the dynamic change of N, P, K elements content in two total nutrition index fertilization mode performed relatively steady trend, but that in two concentrated fertilization mode performed major fluctuations and gradually declined, and demonstrated the phenomenon which was higher than that of two total nutrition index fertilization mode in early period and later lower than theirs, expecially for the 50mg N per-plant total nutrition concentrated fertilization mode. This was probably because of the total nutrition index fertilization mode had obvious advantages and sustainability to the growth of Eucalyptus seedling.(7) Fertilization have significant effect on N, P, K, Ca and Mg elements accumulation of seedlings. Compared with the traditional fertilization mode,the total nutrition concentration fertilization mode and total nutrition index fertilization mode had advantages for seedling to absorb nutrient elements, so that could effectively increase the N, P, K, Ca and Mg elements accumulation of seedling, particularly for 50mg N per-plant total nutrition index fertilization. Except the N、K and Mg elements accumulation of 50mg N per-plant total nutrition concentrated fertilization had some descend, with the passage of time, the N、P、K、Ca and Mg elements accumulation of four fertilization mode in general presented rapid increase on early period and slowly later, but no-fertilization was basically showed a slower increase trend. Both the total nutrition index fertilization mode were better to maintain nutrients balance in Eucalyptus seedling, the ratio of nutrient elements was similar to that of applied nutrient solution, and the two concentrated fertilization mode and no-fertilization would easily led to nutrient imbalance in seedlings.(8) The fertilizer use efficiency of different fertilization mode was obvious difference.The fertilizer use efficiency of two total nutrition index fertilization mode both in some degrees higher than that of two mode of total nutrition concentrated fertilization and no-fertilization, in which The fertilizer use efficiency of 50mg N per-plant total nutrition index fertilization was the highest. This showed that total nutrition index fertilization mode would better improved the fertilizer use efficiency.(9) At the end of the experiment (The first 10 weeks after fertilization), fertilization mode had certain effect to the N, P, K, Ca and Mg element content in light matrix, the greatly influences was K element content, the smaller influences was Mg element content. By the comparison from before and after fertilization, the N element content of all fertilization mode all appear to drop; the P element content mostly appear to increase excepted the no-fertilization; the K element content only appear to drop in the traditional mode and no-fertilization, others were all rised; the Ca and Mg element content both increase in some degrees. Besides,compared with other fertilization mode, the nutrient elements content in light matrix of 50mg N per-plant total nutrition index fertilization mode and 25mg N per-plant total nutrition index fertilization mode, which decrease or increase rate was relatively small, could be better to make the nutrient elements content keep relatively stable, while other fertilization modes could not. Excessive drop may cause empty the nutrition of matrix, which would against fertility maintaining and late seedling growth, Excessive increase may cause large nutrient residue in the matrix, not only waste fertilizers but also could cause secondary moderate growth and environment pollution.(10) Orthogonal test results showed that, in the total nutrition index fertilization mode, the N applicationrates and fertilization starting point had big effect to seedling height, ground diameter and plant biomass, while the length of fertilization time didn’t effect much. In seedling height, ground diameter, biomass and seedling quality index of evaluation indexes, the optimal combination respectively were A1B1C2、A1B1C2、A1B1C1 and A1B1C1.(11) Applied DRIS nutrition comprehensive diagnosis method to analysis the nutrition in light matrix of eight test. Nutrition diagnosis results indicated that the processing of nutrient unbalance index from high to low order was : 5#>3#>4#>test3>2#>test2>1#>test4, this showed that the nutrition of 5# no-fertilization was the most unbalanced one. From the order of requiring fertilizer by nutrition diagnosis, 3#、4# and 5# were all scarce for N, K fertilizer. In general, the proportion of nutrient elements of 1#,2#, test2, test3 and test4 were relative balance, which explain the total index fertilization was more favorable to keep the balance of nutrients in the plant.(12) In seedling height, ground diameter, biomass and seedling quality index of evaluation indexes, orthogonal test results of main nutrient elements ratio in total nutrition index fertilization mode showed that, only the Ca ratio had obvious effect to seedling growth others all didn’t work, this indicated that in the total index fertilization mode of this test, which adopts the main nutrient nutrition elements ratio was more reasonable. The corresponding relatively optimal combination for seedling height, ground diameter, biomass and seedling quality index was A2B2C2D2、A1B1C2D3、A3B3C3D3 and A3B3C2D2.(13) The cultivate matrix of eucalyptus container seedling had an obvious effect to growth, but there was different between growth index and fertilization mode. In the no-fertilization and 25mg N per-plant total nutrition index fertilization mode, the seedling height and biomass of Eucalyptus seedling cultivated by yellow soil were both higher than that cultivated by light matrix, but it was opposited in the 50mg N per-plant total nutrition index fertilization mode. In three kinds of fertilization mode, the Eucalyptus seedling diameter and quality index of light matrix were shown better than that of yellow soil.The best fertilization mode would be different in different cultivate matrix. The 25mg N per-plant total nutrition index fertilization mode in the cultivate matrix of yellow soil performed best, of which the Eucalyptus seedling height, ground diameter, biomass and seedling quality index were all the highest, and also showed that 25mg N per-plant total nutrition index fertilization mode > 50mg N per-plant total nutrition index fertilization mode >no-fertilization(CK); Meanwhile the 50mg N per-plant total nutrition index fertilization mode in light matrix performed best, of which the Eucalyptus seedling height, ground diameter, biomass and seedling quality index were all the highest. It had important practical significance to production of Eucalyptus seedling in the future.The cultivate matrix had a significant effect to the element content of N, P, K, Ca, Mg in Eucalyptus seedling, especially for N、K elements. In the cultivate matrix of yellow soil, of three fertilization modes, element content of N in Eucalyptus seedling in 25mg N per-plant total nutrition index fertilization mode was the highest, other elements content were basically higher in 50mg N per-plant total nutrition index fertilization mode. This was different from the light matrix. The cultivate matrix had a significant effect to the element accumulation of N, P, K, Ca, Mg in Eucalyptus seedling. In the cultivate matrix of yellow soil, of three fertilization modes, element accumulation of N, P, K, Ca, Mg in Eucalyptus seedling in 25mg N per-plant total nutrition index fertilization mode was the highest; but 50mg N per-plant total nutrition index fertilization mode was the best in light matrix. This variation was similar to seedling growth index.更多还原