【作者】 臧国长；

【导师】 马祥庆；

【作者基本信息】 福建农林大学 ， 森林培育， 2008， 硕士

【摘要】 合理施肥是定向培育短轮伐期工业用材林的重要技术措施,开展林木施肥和营养诊断研究是进行合理施肥的前提。桉树是目前世界上重要的造林树种之一,我国桉树人工林面积已超过200万hm~2。福建闽南地区桉树造林已成为外商投资热点和当地的支柱产业之一,但由于长期以来缺乏对桉树人工林施肥方面的系统研究,导致生产上出现了桉树人工林地力衰退和盲目施肥现象,成为当前生产中急需解决的重大课题。鉴于此,本研究以福建桉树的主栽品种—尾巨桉无性系(DH-3229)为研究对象,通过对福建主要桉树种植区尾巨桉人工林的全面调查,研究闽南主要桉树种植区的土壤肥力、施肥状况、林木生长、营养状况及其相互关系:在此基础上,通过室内盆栽试验,研究不同N、P、K配比施肥对尾巨桉生长的影响,揭示尾巨桉生长对养分的需求规律,建立尾巨桉营养诊断指标体系,筛选出适合闽南地区应用应用的桉树施肥配方,以指导福建尾巨桉人工林的科学施肥。主要研究结果如下:1、对闽南主要桉树种植区土壤的调查表明:目前闽南主要桉树种植区尾巨桉人工林的土壤肥力一般介于Ⅲ～Ⅳ类地之间,在福建属中等偏下肥力水平。总体上,林地土壤呈酸性,林地土壤全N、全K和有机质含量中等,全P含量不高,速效养分含量均偏低,其中速效P缺乏严重,可能成为桉树生长的主要限制因子;闽南主要桉树种植区林地土壤物理性质一般,土壤较为紧实,通气性和透水性较差:闽南6个不同桉树种植区林地土壤肥力存在一定差异,其中以长泰、南靖种植区林地的土壤肥力相对较好,云霄种植区林地土壤肥力较差。与南方主要桉树种植区相比,闽南主要桉树种植区林地的土壤肥力相对较好,与广西桉树种植区土壤肥力较为相近,优于广东和海南桉树种植区林地。2、对闽南主要桉树种植区尾巨桉人工林施肥的调查表明:在闽南主要桉树种植区,经营者均已认识到了桉树施肥的重要性,所有的尾巨桉人工林经营均有施肥;施肥方式分为基肥和追肥两种,施肥时间多集中在桉树种植后的前两年,施肥以复合肥、钙镁磷和桉树专用肥为主,有机肥和微量元素肥料施用较少,目前施肥仍处于无序的盲目状态,对施肥肥料的种类和施用量均存在很大随意性,急需科学的施肥和营养诊断体系。3、对闽南主要桉树种植区尾巨桉人工林生长的调查表明:闽南尾巨桉人工林生长迅速,特别是在种植后的前三年均处于速生期,16月龄尾巨桉树高月均生长量可达0.49 m,胸径月平均增长量为0.41 cm;28月龄尾巨桉生长速度变缓,树高和胸径月平均生长量分别为0.42 m和0.34 cm。在闽南6个主要桉树种植区中,长泰的尾巨桉人工林生长最好,其次为南靖、仙游和平和,南安和云霄种植区生长较差。4、DRIS营养诊断研究结果表明:闽南尾巨桉人工林叶片的营养平衡处在亏缺状态,其对N、P和Ca的需求量相对较大,对K、Mg等营养的需求量较小。因此尾巨桉施肥时应注意适当加大N肥、Ca肥和P肥的施用量;尾巨桉人工林叶片N、P、K养分浓度的最适比值范围为:P/N=0.1144±0.0169,N/K=0.9739±0.1997,P/K=0.1074±0.0173。5、闽南主要桉树种植区尾巨桉人工林土壤肥力、叶片营养与生长量的相关分析表明:桉树种植区土壤有机质、全N、水解N与桉树树高、胸径、材积的相关性均较大,叶片中N、K、Ca含量与桉树生长量的相关性也较大,其中Ca含量与生长量呈负相关;当土壤水解N、速效P、速效K含量比例为6:1:3或5:1:5,或叶片中N在10.63～12.74 g/Kg、P在1.00～1.42 g/Kg、K在10.64～14.42 g/Kg、Ca在3.52～7.02 g/Kg、Mg在1.93～3.62 g/Kg时,16月龄尾巨桉人工林可获得较好生长量:当土壤水解N、速效P、速效K含量比例为5:1:4或4:1:4.5,或叶片中N在10.69～12.28g/Kg、P在1.20～1.67 g/Kg、K在12.79～14.73 g/Kg、Ca在5.34～6.42 g/Kg、Mg在2.29～4.10 g/Kg时,28月龄尾巨桉人工林可获得较好生长量。6、尾巨桉不同盆栽施肥的试验表明:不同N、P、K配比施肥对尾巨桉树高和地径生长、生物量积累和叶绿素含量均有较大影响,其中以N、P的影响最大,K的影响最小,影响的大小排序为N＞P＞K。N、P、K营养在尾巨桉不同器官中的积累量存在较大差异,在叶中的积累量最大,其次是干,根的积累量最少,表现为叶＞干＞根;三种营养在根和叶中的积累规律表现为N＞K＞P,在干中的积累规律表现为K＞N＞P。不同施肥处理尾巨桉根、干、叶N、P、K的积累量与施肥量密切相关,施肥量过高或过低及施肥配比不合理均会影响尾巨桉对养分的吸收和积累。7、盆栽条件下尾巨桉叶片DRIS营养诊断研究表明:不同施肥处理尾巨桉的需肥顺序与施肥处理基本一致;尾巨桉叶片中N、P、K养分的适宜比值范围为:P/N=0.1084±0.0135,K/N=0.4822±0.0864,K/P=5.3726±1.0924。在本试验条件下,适宜尾巨桉生长的N最佳施肥量为5.48～6.27g/盆,P的最佳施肥量为2.94～3.10g/盆,K的最佳施肥量为1.98～2.31g/盆,此时盆栽土壤中的速效N、速效P、速效K比例为3:1:3或3:1:2.6。更多还原

【Abstract】 Rational Fertilization is an important measure of directional culture for short rotation industrial timber plantation while the implementation of systematic research on forest fertilization and nutrient diagnosis is the precondition of rational fertilization.Now,Eucalypt was one of the most important planting tree species in the world,areas of Eucalypt plantation in china has over 200 hm~2.Planting Eucalypt has become a hot spot of investment and one of the pillar industry in southern Fujian.In this paper, Eucalyptus urophylla×E.grandis clone(DH-3229),one of the main varieties of Eucalypts in the development of Fujian fast-growing and high-yielding plantation was researched for soil degradation because of continuous multigenerational planting and unscientific fertilization in Eucalyptus plantations in the main planting areas in southern Fujian.In such a way that comprehensive investigations for Eucalyptus urophylla×E.grandis plantation woodlands of the main Eucalypt planting areas in southern Fujian were taken to have a deep understanding of status of soil fertility,fertilization,tree growth, nutrition balance and the relations between each other,and based on that,the research of effects on Eucalyptus urophylla×E.grandis growth of indoor pot culture experiments with different proportioning fertilization of N,K,P was made to explore the rules of needs for growth of the objects and primarily establish nutrient diagnosis indexes of the Eucalyptus urophylla×E.grandis,and then,the suitable Eucalypt fertilization formulation should be selected with the purpose of providing scientific fertilization guidance for current Eucalyptus urophylla×E.grandis plantation.Main results are as follows:1.The investigations of fertility condition of Eucalyptus urophylla×E.grandis plantations showed that the fertility condition of Eucalyptus urophylla×E.grandis plantation woodlands in southern Fujian lies between grade 3 and grade 4,it was less middle-level in southern Fujian.In general,the woodland soil were acidity or strong acidity;the content of total N,total K and OM in the soil were at middle level,the content of total P was deficiency,and available nutritions was low,moreover,available P was in serious deficiency,it would be a limited factor for the growth of Eucalyptus.The physical characters of the woodland soil were poorer,it was relatively compact,poor aeration and permeability.There was a certain difference among the 6 different planting areas,the soil fertility status of Eucalyptus urophylla×E.grandis plantations in Changtai and Nanjing was relatively good.However,it was poor in Yunxiao for a low content with total and available nutrient.Compared with other important planting areas,planting area in southern Fujian was at the same level with Guangxi and superior to Guangdong and Hainan.2.Fertilization investigations of Eucalyptus urophylla×E.grandis plantations showed that:the farmers have realized the importance of fertilization during the process of Eucalypt planting,all the plantations had been fertilized with basal fertilizer and top dressing focused on the first two year after it being planted, fertilization was still in disorder with chemical fertilizer mainly used and kinds and application rate greatly at random.3.Growth investigations of Eucalyptus urophylla×E.grandis plantations showed that The first three years was the key period for management after the plantation was founded,during that period,trees grew most rapidly and the influence of soil basic fertility and fertilization on plants growth became more significant as growth period prolonged.Plantations grew most rapidly when they were about 16 months, and became relative slow about 28 months.Among 6 planting areas,the plantations of Changtai country grew best,the secondary was Nanjing,Xianyou and Pinghe,while Nan’an and Yunxiao the worst.4.The result of DRIS nutrition diagnosis showed that:Eucalyptus urophylla×E.grandis plantation in southern Fujian was under poorer nutrition balance with less supply in N,P,Ca and more in K,Mg.so it should enlarge the fertilization amount of N,P and Ca.Through DRIS nutrient diagnosis the optimum ratio range of N,P,K concentration in the leaves of Eucalyptus urophylla×E.grandis plantations was respectively P/N=0.1144±0.0169,N/K=0.9739±0.1997,P/K=0.1074±0.0173.5.The relationship among soil fertility,mineral elements content in leaves and growth of seedling was analyzed by using multifactor interactions stepwise regression method.The results showed that in the Eucalypt planting areas in southern Fujian,there was a strong correlation between the content of OM,total N,hydrolytic N in woodland soil nutrient and tree height,diameter,volume,it showed that N had greater influence on the growth of Eucalyptus urophylla×E.grandis;also,there was a strong correlation between the content of N,K,Ca in leaves and growth of seedling,among them,the content of Ca showed negative correlation with the growth of seedling.For 16 months Eucalyptus urophylla×E.grandis plantations,trees obtained better growth of seedling when the ratio of hydrolytic N,available P and K in the soil was about 6:1:3 or 5:1:5 or when there was amount in the leaves which is N,10.63～12.74 g/Kg;P,1.00～1.42 g/Kg; K,10.64～14.42 g/Kg;Ca,3.52～7.02 g/Kg;Mg,1.93～3.62 g/Kg;and for28months plantations,that was about 5:1:4 or 4:1:4.5 or N,10.69～12.28 g/Kg;P,1.20～1.67 g/Kg;K,12.79～14.73 g/Kg;Ca,2.29～4.1 0g/Kg;Mg,5.34～6.42 g/Kg in the leaves.6.The results of Eucalyptus urophylla×E.grandis growth of indoor pot culture experiments with different proportioning fertilization of N,K,P showed that:different proportioning fertilization of N,P,and K had great influence on tree height,diameter growth,biomass accumulation,and chlorophyll content of Eucalyptus urophylla×E.grandis.Among them,N,P had greater influence but K had less influence.The influence order was N＞P＞K.The accumulation of N,P,K amount in the tissues of roots,stems,leaves has a certain difference,it was great in leaves and less in stems and roots.The accumulation rule of N,P,K amount in the tissues of roots,stems,leaves was leaves＞stems＞roots,representing that leaf is the main organ in nutrients accumulating;The accumulation rule of N,P,K in roots and leaves was N＞K＞P,while in the stems,it was K＞N＞P.The accumulation of N,P,K in roots,stems and leaves which is under different fertilizer treated have a close relationship with fertilization amount,and it would influent the absorption and accumulation in seedling if the amount of fertilizer was too high or too low.7.The results of DRIS nutrient diagnosis of Eucalyptus urophylla×E.grandis leaves under the condition of pot culture showed that:the sequence of fertilizer that seedlings need was at a same order with fertilizer treated sequence.The best ratio scope of N、P、K concentration in the leaf of Eucalyptus urophylla×E.grandis under the condition of pot culture was gained by DRIS nutrient diagnosis and the range was P/N=0.1084±0.0135,K/N=0.4822±0.0864,K/P=5.3726±1.0924.By using regression equation between fertilization amount and growth of seedling,it can be concluded under such experiment conditions that the optimum fertilization amount comfortable for the growth of Eucalyptus urophylla×E.grandis trees is as follows:N,5.48～6.27 g/pot;P,2.94～3.10 g/pot;and K,1.98～2.31 g/pot.Thereby,the ratio of N,P, and K in the pot culture soil shall be 3:1:3 or 3:1:2.6.更多还原