我国桉树人工林施肥现状、存在问题及对策

本文从桉树需肥特性及我国桉树主要种植区土壤肥力状况分析入手,着重论述我国桉树人工林施肥现状,并指出目前我国桉树人工林施肥中存在的主要问题,提出在桉树栽培中使用肥料等相应建议,为我国桉树速生丰产林的可持续经营提供科学施肥依据。     

我国桉树人工林施肥研究进展

科学施肥是实现桉树人工林速生丰产的一个重要措施。本文从桉树人工林施肥研究的历史、桉树种植区的土壤肥力、施肥效应、营养诊断和平衡施肥等方面综述了桉树人工林施肥的研究进展,指出了目前研究中存在的问题和今后的研究方向,为我国桉树速生丰产林的可持续经营提供科学依据。     

全营养施肥对桉树组培容器苗生长和营养状况的影响

在温室条件下对桉树组培容器苗进行全营养施肥与传统单施N肥比较试验,分析测定不同施肥处理对苗木生长、生物量以及养分含量的影响。结果表明,全营养施肥比单施N肥更有利于桉树苗木生长和营养平衡;在全营养施肥中,又以N50 mg.株-1处理优于N100 mg.株-1处理。在N50 mg.株-1基础上,实施全营养施肥是培育优质桉树苗的较佳施肥方案,可供桉树工厂化育苗推广应用。     

浅谈广西桉树施肥

我国从澳洲引种桉树已有近百年历史。桉树具有速生丰产的特性,已成为我国南方栽培的主要树种之一。但对其适生条件和施肥问题仍未解决,因此,有必要进一步研究它的适生条件和施肥问题。一、桉树的天然分市与我国引种情况     

30种澳大利亚桉树引种的育苗研究

在1986.3——1986.6月对25个树种、32个种源澳大利亚桉树进行育苗试验。结果表明:大多数澳大利亚桉树种子较适应昆明气候和所用育苗方法。育苗成功满足了试验需求。其中单蒴盖亚属的3种桉树育苗成功,是国际间桉树引种的一大突破。通过对所育树种种子发芽指数、苗木地上和地下部分生长量观测数据分析,除粉绿桉和少花桉外其它各树种种源苗期表现均较好。     

广西桉树无性系育苗产业化现状及其发展策略

介绍了广西在桉树组培和扦插技术方面的研究发展以及桉树无性系育苗产业化的现状,指出了当前桉树无性系育苗产业化中存在的主要问题,提出了深化桉树无性系育苗产业化的主要措施和策略。     

桉树扦插育苗技术研究的回顾与展望

桉树扦插育苗(以苗繁苗)技术的推广应用,极大地推动了桉树无性系造林的发展和进步。本文通过对雷州林业局桉树无性系繁殖育苗技术研究的回顾和当前桉树扦插育苗的实践经验及存在问题的论述,阐明了今后扦插育苗技术研究领域和发展前景。     

华南土壤肥力特征与桉树施肥

针对我国华南地区土壤肥力特征，桉树的生物学特征及需肥特征，谈谈桉树丰产栽培中的合理施肥问题。     

30种澳大利亚桉树引种的育苗研究

在１９８６．３－１９８６．６月对２５个树种、３２个种源澳大利亚桉树进行育苗试验。结果表明：大多数澳大利亚桉树种子较适应昆明气候和所用育苗方法。育苗成功满足了试验需求。其中单蒴盖亚属的３种桉树育苗成功，是国际间桉树引种的一大突破。通过对所育树种种子发芽指数、苗木地上和地下部分生长量观测数据分析，除粉绿桉和少花桉外其它各树种种源苗期表现均较好。     

华南土壤和特征与桉树施肥

针对我国华南地区土壤和特征，桉树的生物学特征及需肥特征，谈变桉树丰产栽培中的合理施肥问题。     

Effects of contrasting fertilization and moisture regimes on biomass,nutrients, and water relations of container grown red pine seedlings

Red pine seedlings were grown for 16 weeks under contrasting fertilizat (conventional, exponential) and moisture (wet, moist, dry) regimes to assess preconditioning effects of treatments on biomass production, nutrient uptake and allocation, and water relations. Growth, nutrient status, and water relations were affected more by moisture availability than by fertilization regime. Exponential fertilization under limited irrigation lowered shoot/root mass ratio, increased root nutrient reserves, and enhanced drought avoidance compared to conventional fertilization regimes. Drought treatments decreased nutrient uptake in the shoots of both fertilization regimes by 24%, but increased nutrient accumulation in the roots by 39% in the exponential regime compared to 17% in the conventional. These results may explain improved outplanting performance noted for exponentially fertilized container stock.     

Premature shoot growth termination allows nutrient loading of seedlings with an indeterminate growth strategy

Nutrient loading of nursery seedling stock of species with an indeterminate growth strategy is challenging and poorly understood. Here, we explore the use of two potential techniques for nutrient loading of trembling aspen (Populus tremuloides Michx.) seedlings: (1) exponential fertilization and (2) early shoot growth termination in order to divert assimilated nutrients and carbon to storage rather than to growth. In the first study, aspen seedlings were treated with either exponential or constant fertilization rates, both of which supplied the same amount of nutrients over the growing season. Exponential fertilization resulted in overall poor planting stock form (stunted seedling growth and weak root development) and produced only marginal improvements of nutrient status. As a result, the exponential fertilization regime studied cannot be recommended as a treatment for aspen seedlings. In the second study we treated seedlings with a 2 × 2 factorial combination of fertilization and shoot growth inhibitor (SGI) applications with the fertilizer treatments varying in terms of mid-season fertilizer concentrations. Seedlings with SGI application had much higher tissue nutrient and carbon reserve concentrations than seedlings without a SGI application. In addition, nutrient uptake appeared to be more efficient in SGI treated seedlings, which could potentially result in significant reductions of nutrient application rates during aspen seedling production in nurseries. Overall, early shoot growth termination using a SGI appears to be an effective technique to produce nutrient loaded aspen seedlings.     

不同氮素施肥方法对尾巨桉苗期生长和光合生理特性的影响

采用3种不同的氮素施肥处理(平均施肥、直线施肥和指数施肥)对尾巨桉苗木进行施肥处理,结果显示：指数施肥获得的苗木苗高和地径均大于其他施肥处理;指数施肥下尾巨桉苗木的叶、茎、根和地上部分干质量和整株生物量均显著大于其他施肥处理,指数施肥获得了更多的苗木生物量;3种施肥处理下,指数施肥的苗木净光合速率 Pn、气孔导读 Gs 和蒸腾速率 Tr 均为最大值,且显著大于其他处理。因此,3种施肥方法中,指数施肥方法最利于尾巨桉苗木的生长和光合作用。     

Growth regulation of Scots pine seedlings with different fertilizer compositions and regimes

Scots pine (Pinus sylvestris L.) seedlings were grown in containers filled with peat, using two different fertilizers and three different fertilizer regimes. Seedling shoot and root growth and shoot content of nitrogen, potassium and phosphorus were followed in the nursery and after outplanting in the field. Attempts to regulate growth rate by an exponential nutrient supply were not successful, but the root/shoot ratio was influenced by the fertilization regime. Internal nitrogen concentration was stable only for seedlings with low relative growth rate, while seedlings with high nutrient supply in the nursery showed strong nutrient dilution in the shoot after planting.     

Weed control increases nitrogen retranslocation and growth of white spruce seedlings on a reclaimed oil sands soil

Early establishment of seedlings in reclaimed oil sand areas is often limited by low nutrient and water availability due to factors such as strong understory vegetation competition. Management practices such as nursery fertilization and field weed control could help early establishment of planted seedlings and reclamation success. We investigated the effect of nursery nutrient loading and field weed control on the growth, nitrogen (N) retranslocation within seedling components, and plant N uptake from the soil for white spruce (Picea glauca [Moench] Voss) seedlings planted on a highly competitive reclaimed oil sands site for two years. Exponential fertilization during nursery production increased the root biomass but not the nutrient reserve in the seedling. In the field experiment, on average across the treatments, 78 and 49% of the total N demand of new tissue growth in the first and second year were met by N retranslocation, respectively. Though exponential fertilization did not affect N retranslocation, it increased the percent height and root collar diameter growth. Weed control increased not only the growth of seedlings by increasing soil N availability, but also N retranslocation within the seedlings in the second year after outplanting. We conclude that vegetation management by weed control is feasible in improving the early growth of white spruce seedlings planted on reclaimed soils and facilitate tree establishment in the oil sands region. Optimization of the nursery exponential N fertilization regime for white spruce may further help with early revegetation of reclaimed oil sands sites.     

桉树接种固氮菌效果的研究

试验表明接种固氮菌能显著提高桉树苗木的生长及苗木各器官的生物量和Ｎ含量,接种苗木高生长比对照（不接种）增加２９．８１％、叶片数增加３７．３１％、叶片干重增加３５．０１％、茎干重增加５５．５９％、根干重增加７８．９３％、总生物量干重增加５５．８９％。不同菌株的增产效果存在差异,接种催娩克氏菌的效果较接种阴沟肠杆菌的好。接种＋施Ｎ８０ｍｇ／株处理的效果优于接种＋施Ｎ３０ｍｇ／株处理的效果。接种与施Ｎ肥的分析结果表明接种催娩克氏菌的效果等于施Ｎ８０ｍｇ／株的效果。     

N素指数施肥对降香黄檀及土壤N、P化学计量特征的影响

以降香黄檀（Dalbergia odorifera）苗木为研究对象,用氮素指数施肥法对降香黄檀苗木进行 梯度施肥处理,探讨N 素指数施肥对苗木及土壤氮、磷元素含量及化学计量特征的影响。结果表明,指 数施肥显著影响了植株体内各器官及土壤N、P 含量,随着施肥量的增加,植株体内各器官及土壤N、P 含量呈现逐渐增加的趋势;指数施肥同时影响了植株和土壤的N/P,施肥处理下的植株和土壤N/P 显著 低于未施肥处理。相关分析表明,植株与土壤的元素含量和化学计量存在显著的相关关系。通过叶片 N/P 比值对生长状况进行判断可知,试验中段植株生长受 N、P 元素共同限制,试验结束时则主要受 P 元素限 制。研究表明,N 素指数施肥能够有效提高降香黄檀体内各器官元素含量,在苗木抚育时应注意加强施 肥以促进苗木生长。     

容器苗指数施肥研究综述

容器苗作为主要的造林材料广泛用于林地更新和荒山的植被恢复, 但其造林成活率及生长表现常受杂草和土壤肥力的影响。指数施肥作为一种新型的容器苗培育方式, 将施肥量与植物指数生长期间的需肥量紧密结合, 并通过营养载荷在幼苗体内建立营养库, 从而降低了幼苗对种植地营养水平的依赖, 有利于提高幼苗的造林成活率。文中介绍了指数施肥的原理, 及其对苗期和种植后幼苗生长的影响, 旨在为容器苗指数施肥在我国的推广提供理论基础。     

Minimizing nutrient leaching and improving nutrient use efficiency of Liriodendron tulipifera and Larix leptolepis in a container nursery system

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The optimal fertilization practice is that which maximizes seedling growth and minimizes nutrient loss. We tested three fertilization strategies: (1) constant fertilization (2) a three-stage rate, and (3) exponential fertilization on Liriodendron tulipifera and Larix leptolepis containerized seedlings. Growth performance, nutrient uptake, and nutrient loss in leaching were measured. Height, root collar diameter, and dry weight of both species were not significantly different among treatments even though the nutrient supply of the exponential treatment was half that of the constant and three-stage treatments. Generally, nutrient losses in leached solutions were higher in constant and three-stage than the exponential treatment. Nutrient use efficiency was calculated as the ratio of the nutrient content of the seedlings to the amount of nutrient applied to the containers. The nitrogen use efficiency in the constant, three-stage, and exponential treatments was 63, 61, and 85% for yellow poplar, respectively, and 35, 30, and 53% for larch. Similar results were obtained for phosphorus and potassium. Thus, the exponential treatment had the highest nutrient use efficiency as well as the least nutrient loss. Adjusting fertilization rates can reduce soil and water contamination around the nursery without compromising growth performance, which reduces both producer’s investments and environmental impacts.     

桉树苗期抗瘿姬小蜂能力研究

桉树瘿姬小蜂主要危害桉树苗圃及幼林。通过对15种桉树实生苗不同部位感瘿姬小蜂状况的调查结果表明：卡特桉未感病,柳桉各部位虫瘿最多。相关分析表明苗高与嫩枝虫瘿数存在显著相关,茎杆和嫩枝虫瘿数与总虫瘿数间存在极显著相关。不同桉树品种的茎杆和总虫瘿数差异极显著（P〈0.01）,嫩枝虫瘿数差异显著（P〈0.05）。