共查询到20条相似文献，搜索用时 444 毫秒
1.
底部渗灌条件下水肥对华北落叶松容器苗生长及基质pH值、电导率的影响 总被引：3，自引：0，他引：3
【目的】探索底部渗灌条件下华北落叶松容器育苗的最佳水肥组合,完善华北落叶松容器育苗技术,为规范底部渗灌技术下容器育苗提供科学参考。【方法】以华北落叶松播种容器苗为研究对象,采用完全随机区组设计,设5个灌水梯度、3个施肥浓度,共15个水肥处理,对华北落叶松容器苗培育1年,通过对苗木生物量及根系形态结构、基质化学性质等指标进行测定并与对照相比较,研究容器苗底部渗灌条件下不同水肥处理对华北落叶松苗木生长、根系形态结构及基质化学性质的影响,探讨水肥效应与苗木质量之间的关系,从而找出华北落叶松容器苗底部渗灌的最佳灌水量和缓释肥量。【结果】苗木生物量及根系形态指标均随灌水梯度及施肥量的增大呈先逐渐增大再减小的趋势;根冠比随水分梯度的增大逐渐减小,随施肥量的增加呈先增后减的趋势;底部渗灌条件下,华北落叶松当年生容器苗最佳水肥组合为75%灌水梯度和100 mg·株－1施氮量,此处理下的苗木生物量达到0.64 g·株－1,根系细根(0.0＜D≤0.5 mm)所占比例最大,根累计长度、根累计表面积和根累计体积分别为82%,62%和46%。各处理的基质 pH5.5～6.5之间,电导率0.75～2.0 mS·cm －1,均在苗木生长的适宜范围内。【结论】与上方灌溉相比,底部渗灌下适宜的水肥配比利于苗木根系的生长,细根更发达,利于苗木吸收营养,苗木质量明显提高;而且底部渗灌条件下育苗基质的 pH值、EC 值均在植物生长安全范围内,这为底部渗灌技术在我国造林树种容器育苗中的应用提供理论依据。 相似文献
2.
容器规格和基质配方对红锥幼苗生长及造林效果的影响 总被引：3，自引：0，他引：3
《林业科学》2017,(3)
【目的】通过对不同容器规格和基质配方条件下1,2年生红锥幼苗生长及造林效果对比分析,为2种年龄红锥苗木培育筛选出适宜的容器规格和基质配方,亦为其造林适宜苗龄的选择提供科学依据。【方法】采用2种容器规格和11种基质配方分别培育1,2年生红锥苗,测定红锥苗期的生长动态,并开展造林试验,调查其早期生长表现。运用方差分析、多重比较等方法,探明不同容器规格和基质配方条件下红锥幼苗生长差异,应用相关分析揭示红锥苗期生长与造林效果的相关性。【结果】容器规格和基质配方显著影响1,2年生红锥苗的苗高、地径、根生物量和总生物量(P0.05),且两者交互作用对1,2年生幼苗的苗高、地径、根生物量以及2年生幼苗的总生物量具有显著影响。1年生红锥苗造林当年,各基质配方的造林保存率差异不显著(P0.05),而幼树高差异显著;造林第2年,各基质配方的造林保存率和幼树高差异不显著,而地径差异显著。2年生红锥苗造林当年,各容器规格的造林保存率、幼树高和地径均差异显著,各基质配方的造林保存率差异不显著,而幼树高和地径差异显著。容器规格和基质配方的交互作用对2年生红锥苗造林当年幼树高具有显著影响。1年生红锥苗造林,当年幼树高、第2年幼树高和地径与造林前苗高、地径、根生物量和总生物量呈显著正相关,且当年和第2年幼树高与造林前幼苗根冠比呈显著负相关。2年生红锥苗造林,容器规格1(8 cm×12 cm,直径×高)当年幼树高、地径与造林前苗高和总生物量呈显著正相关,容器规格2(12 cm×15 cm,直径×高)当年幼树高与造林前苗高、地径、根生物量和总生物量呈显著正相关,而当年幼树地径与造林前总生物量呈显著正相关,表明红锥苗木质量显著影响其前两年造林效果。【结论】容器规格与基质配方对1,2年生红锥苗木生长存在交互作用,因此红锥苗期适宜基质配方选择应依据苗龄和容器规格而定。培育1年生红锥苗,建议采用容器规格1和基质配方10(50%沤制树皮+25%黄心土+25%锥林表土);培育2年生红锥苗则采用容器规格2和基质配方7(50%沤制树皮+50%锥林表土)。在杂灌控制及时的良好立地,采用容器规格1培育1年生红锥苗,其造林效果优于容器规格2培育的2年生红锥苗。 相似文献
3.
《中南林业科技大学学报(自然科学版)》2015,(4)
以2种规格的硬塑料容器和2种规格的无纺布容器为试验材料,培育华北落叶松容器苗,采用嵌套实验设计,并用底部渗灌技术为苗木提供水分,通过比较苗木形态指标和营养元素,研究容器类型及规格对底部渗灌下华北落叶松容器苗的影响。结果表明:硬塑料容器苗木的苗高、地径及单株生物量较无纺布容器高出31%、39%及71%,根和茎中的氮含量是无纺布容器的4倍和3.7倍;长规格容器仅明显促进苗木根系的生长,根生物量和根氮含量较短规格容器分别高出36%和25%。因此,在底部渗灌下培育华北落叶松容器苗,保水保肥性强的硬塑料容器可培育出高质量苗木;从节约成本的角度出发,短规格容器可应用于底部渗灌下一年生华北落叶松容器苗的培育。 相似文献
4.
容器类型和胚根短截对栓皮栎容器苗苗木质量及造林初期效果的影响 总被引：2，自引：0，他引：2
《林业科学》2017,(6)
【目的】容器类型和胚根短截可有效调控苗木质量,同时采用2种措施培育苗木,从苗圃和造林2个阶段探讨对苗木质量的叠加效应,为丰富苗木质量的调控措施提供参考。【方法】以栓皮栎容器苗为研究对象,将胚根短截(RP)和不短截对照(CK)的种子分别播在2种容器(D40,Slit)中,测定苗圃阶段栓皮栎根系结构、生长、养分浓度和造林效果。【结果】容器类型和胚根短截的交互作用对根系结构和养分浓度影响显著,D40-CK组合促进2 mm径级根系发育,并提高根系总表面积和体积,而D40-RP组合有利于提高K浓度,证实2种育苗方式组合研究的必要性。主效应表明,D40容器更加有利于2~5 mm径级根系发育和苗木地上部分的生长,但导致苗木根茎比下降;造林1年后依然促进幼树高和地径生长;造林2年后,促进作用消失。胚根短截抑制5 mm径级根系发育,并且对苗高、地径和根生物量有负面影响;造林1年后,对幼树高和地径的抑制作用依然存在;造林2年后,胚根短截处理的成活率显著降低,但促进根系生长和养分吸收。【结论】苗木根系结构、生长、养分和造林初期效果证实采用容器类型和胚根短截组合调控苗木质量的必要性。培育主根发达树种栓皮栎的最佳组合为D40容器和胚根不短截(CK)。 相似文献
5.
容器类型及规格对油松容器苗底部渗灌耗水规律及苗木生长的影响 总被引：2，自引：0，他引：2
《林业科学》2016,(6)
【目的】研究底部渗灌条件下不同类型和规格的容器对油松容器苗耗水规律及生长的影响,以期初步筛选底部渗灌条件下培育油松苗的最适容器类型和规格,为底部渗灌技术在油松容器苗培育上的推广和应用提供理论依据。【方法】采用嵌套设计,选用口径为3.8 cm、长度为14 cm和21 cm的硬塑料容器,口径为4.5 cm、长度为10和15cm的无纺布容器以及口径为10 cm、长度为10和15 cm的黑色塑料容器培育油松苗,并用底部渗灌的方式给予苗木水分,通过测定底部渗灌期间苗木的灌水频率和耗水量及1年生长期结束后苗木的苗高、地径、主根长等指标,探讨不同类型和规格的容器对底部渗灌条件下的油松苗耗水规律和生长的影响。【结果】底部渗灌期间总耗水量表现为无纺布容器黑色塑料容器硬塑料容器,均值分别为每株1 453,964,442 m L。灌水频率则表现为无纺布容器硬塑料容器黑色塑料容器,长规格的硬塑料容器水分利用率最大。苗木苗高和地径均以硬塑料容器最大,长规格和短规格的硬塑料容器苗高均达到了15 cm,地径也均在2.6 mm以上。硬塑料容器茎干质量最大,尤其是长规格的硬塑料容器茎干质量为0.4 g。黑色塑料容器根干质量最大,尤其是长规格的黑色塑料容器根干质量为0.65 g。但黑色塑料容器中苗木主根长均值达到23 cm。无纺布容器苗木苗高、地径、生物量均处于最低水平。苗木质量指数(QI)表现为黑色塑料容器硬塑料容器无纺布容器,其中,长规格的黑色塑料容器QI值最大,为2.48。硬塑料和黑色塑料容器的根总长、根表面积、根体积和比根长无显著差异,但均明显大于无纺布容器(P0.05)。【结论】硬塑料容器耗水量最低,水分利用率却最高,且培育的苗木质量最好,因此在底部渗灌下培育油松容器苗,硬塑料容器较其他2种容器类型更为合适;而黑色塑料容器虽培育的苗木大,但却出现了窝根;无纺布容器培育的苗木质量显著低于其他2种容器类型,且耗水量大,水分利用率低。3种容器类型下,长规格的容器均可促进苗木的生长。 相似文献
6.
【目的】探究不同子叶切除强度和苗圃施肥对栓皮栎容器苗造林效果的影响,为丰富苗木质量调控技术提供参考。【方法】采用双因素试验设计,设置3种子叶切除强度(E1/3、E1/2、E2/3)和不切除对照(E0)设置,同时2种苗圃施肥处理(N0、N100),施入相同量的磷钾肥和微量肥料,调查分析生长季末栓皮栎苗高、地径和生物量以及造林1年后苗木形态、养分积累和光合特性。【结果】苗圃不施肥条件下,子叶切除处理均降低造林苗木生物量、养分含量和光合特性。苗圃施肥条件下,E1/3、E1/2处理苗木造林1年后主根生物量较对照(E0)分别增加21.9%、31.7%,侧根生物量分别增加41.4%、45.2%;E1/3、E1/2处理还提高造林苗木根系养分含量和光合特性,促进苗木对光能的利用与碳同化;E1/2处理对单株生物量和养分含量也有显著促进,对光合特性的促进效果比E1/3更佳;而E2/3处理苗木造林后生长受到严重抑制,苗圃施肥并未起到缓解作用,表明子叶自身养分对于苗木发育具有不可替代的地位,苗圃施肥效果有赖于子叶养分丢失程度。从苗圃和造林2个阶段评价子叶切除效应更为可靠;在子叶切除对造林苗木生长的影响评价过程中,苗木光合特性和生物量、养分含量同等反映苗木生长状况,是评价子叶切除效应的有效、便捷指标。【结论】适度切除子叶结合苗圃施肥有利于提高栓皮栎容器苗造林效果,切除1/2子叶结合苗圃施肥(每株100 mg N)培育栓皮栎容器苗造林效果最佳。 相似文献
7.
添加园林废弃物堆肥基质对栓皮栎容器苗生长的影响 总被引：1，自引：0，他引：1
以园林废弃物堆肥部分替代东北泥炭—珍珠岩混合基质中的东北泥炭,分析了添加园林废弃物堆肥对栓皮栎容器苗基质及苗木生长情况的影响。研究表明:添加堆肥降低了基质密度,改善了基质酸碱环境,提高了全氮含量,同时也造成了EC值的偏高;在高堆肥配比下,出苗率显著降低,但也能达到80%的生产指标;堆肥配比≤25%时,苗高、地径、高径比、主根长及根生物量等指标与对照之间无显著差异,且栓皮栎容器苗的茎根比有所降低。该试验条件下,栓皮栎容器苗基质的最佳比例配比为东北泥炭55%、珍珠岩20%、园林废弃物堆肥25%。 相似文献
8.
氮肥和容器深度对栓皮栎容器苗生长、根系结构及养分贮存的影响 总被引：2，自引：0，他引：2
《林业科学》2016,(4)
【目的】氮肥施用量或容器深度可有效调控苗木质量,本研究同时采用2种措施培育容器苗,探讨2种措施对苗木质量提升的叠加效应,为丰富苗木质量调控措施提供参考。【方法】以1年生栓皮栎容器苗为试验材料,采用双因素完全随机试验设计,设置2个施肥水平(100 mg N·株~(-1))及2个容器深度(25,36 cm),通过测定第1年生长季末栓皮栎苗高、地径、生物量、养分浓度以及不同径级根系体积、表面积、长度。【结果】施氮肥与容器长度交互效应对根氮浓度和中等径级根系(2~3 mm)的根体积、表面积显著,25 mg N-36 cm组合有利于中等根系径级生长,100 mg N-36 cm组合有利于根系氮浓度提高,这表明交互效应对地下部分的影响大于地上,2种措施交互作用通过影响根系来调控苗木质量。主效应表明,充足施肥量有利于地径生长、根氮和钾浓度提高;容器长度对根系结构的影响较施氮量显著,深容器可促进根系径级为3~4 mm的根系发育,否则造成窝根;长容器可促进苗高生长、茎生物量积累以及茎氮浓度提高。【结论】苗木生长、养分、根系结构对施氮量与容器深度的交互效应与主效应响应规律证实2种措施相结合调控苗木质量的必要性。主根发达树种栓皮栎容器苗最佳组合为100 mg N和36 cm深的容器。 相似文献
9.
《四川林业科技》2021,(4)
浙江樟(Cinnamomum chekiangense)是重要的珍贵树种,在大力推广珍贵树种造林中,优质容器苗的培育是造林成功的关键,而育苗基质直接决定着苗木质量。本文以浙江樟1年生苗为研究对象,采用盆栽的方法,研究5种不同配比基质(黄泥、锯末、泥炭)对苗木株高、地径、生物量的生长和氮磷钾养分积累的影响,旨在筛选出适合浙江樟容器苗培育的基质配比,为优质容器苗的培育提供基础。结果表明A3(黄心土︰泥炭︰锯末=40︰30︰30)基质最有利于浙江樟的生长,株高和地径均显著高于A5(P0.05);A3基质培育的浙江樟叶片、枝干、根系和总生物量均为最大,分别为33.63,39.57,48.43,121.64 g·株~(-1),显著高于其他处理(P0.05);浙江樟全株氮、磷、钾积累量以A3基质为佳,分别为3 168.8,137.3,673.1 mg·株~(-1);灰色关联度法评价表明,A3基质是浙江樟容器苗生长的最优基质。 相似文献
10.
为给底部渗灌应用于育苗生产提供理论依据,以薄壳山核桃1年生容器实生苗为试材,研究了底部渗灌对不同生长时期的幼苗根系活力及保护酶类的影响。结果表明,底部渗灌显著促进了生长初期薄壳山核桃容器苗根系TTC还原强度,达到362.83μg/(g·h),显著高于上方喷灌苗木根系还原强度,且生长中后期也能保持较高水平的根系活力;底部渗灌处理后,苗木根系MDA含量及SOD、POD和CAT保护酶活性变化趋势与上方喷灌苗木一样,均表现出先上升后下降的趋势,说明底部渗灌对生长初期苗木根系有一定的胁迫,苗木通过提高根系中保护酶的活性减轻伤害,不断适应根系环境。 相似文献
11.
Acevedo Manuel Álvarez Carolina Cartes Eduardo Dumroese R. Kasten González Marta 《New Forests》2020,51(1):159-174
Ruil (Nothofagus alessandrii) is an endangered keystone species from the Mediterranean climate zone of Chile. Ruil’s fragile state of conservation urges development of restoration programs, but specific protocols for nursery production and field establishment that ensure plant survival are largely unknown. Therefore, we examined the effect on nitrogen (N) fertilization and container size during nursery production in combination with the use of mesh shelters after outplanting on survival and growth during the first growing season in the field. First year outplanting survival of nursery-grown container seedlings was enhanced when seedlings were given nitrogen (N) during nursery production and deployed with mesh tree shelters in the field. The volume of the container had no effect on outplanting survival and growth. Increasing N from zero to 200 mg N L?1 provided sufficient N levels, resulting in increased seedling height, root-collar diameter, shoot biomass, and total seedling N and phosphorous concentrations. Additional N provided by the 400 and 600 mg N L?1 treatments underwent luxury consumption by the seedlings with no further benefits in field performance. Improved growth in the nursery, along with the use of mesh tree shelters after outplanting, especially during the typical summer drought, may be responsible for increased survival during the first growing season. Increasing the performance of nursery-grown ruil seedlings is essential to restoring this endangered, vulnerable, and foundation species within the highly biodiverse, yet seriously threatened endemic Maulino Costero Forest of the Mediterranean climate of central Chile.
相似文献12.
Juan A. Oliet María Tejada K. Francis Salifu Aleyda Collazos Douglass F. Jacobs 《European Journal of Forest Research》2009,128(3):253-263
Holm oak (Quercus ilex L.) seedlings were exponentially (E) nutrient loaded using incremental increases in fertilizer addition or conventionally
(C) fertilized using a constant fertilizer rate during nursery culture. The fertility treatments (mg N plant−1) were control (0), 25E, 100E, and 100C. Subsequently, 1-year-old plants were transplanted under simulated soil fertility
gradients in a greenhouse to evaluate effects of nutrient loading and post-transplant fertility on seedling performance. Post-transplant
fertility consisted of fertilizing plants at two rates (0 vs. 200 mg N plant−1). A water-soluble fertilizer 20-20-20 was supplied in both nursery and post-transplant experiments. Nutrient loading increased
plant N content by 73% in 100E and by 75% in 100C relative to controls, although no significant differences were detected
between constant and exponential fertilization regimes at the 100 mg N plant−1 rate. When transplanted, nutrient loading promoted post-transplant root growth relative to shoot, implicating potential to
confer competitive advantage to loaded holm oak seedlings after trans-planting. In contrast, post-transplant fertility increased
new shoot dry mass by 140% as well as N, P and K content relative to controls. Results suggest that holm oak seedlings can
be successfully nutrient loaded in the nursery at higher fertility rates, improving its potential to extend new roots, but
alternative fertilization regimes and schedules that better fit nutrient availability to the growth rhythm and conservative
strategy of this species must be tested. 相似文献
13.
Quantifying root system quality of nursery seedlings and relationship to outplanting performance 总被引：2，自引：2，他引：2
With over 1.5 billion forest tree seedlings produced annually in the USA, seedling quality assessment is critical to ensure reforestation success. While height and root-collar diameter are the most common traits evaluated during seedling quality assessment, above-ground morphology is not always an accurate predictor of performance after outplanting. Root system morphology and physiological status may provide a more accurate indication of seedling potential. However, relatively few studies have attempted to quantitatively assess root system quality in relation to outplanting success. Large root volume, high root fibrosity, and an increased number of first-order lateral roots have shown some correlation to improved field performance. Physiological seedling quality assessment is commonly practiced through evaluation of root growth potential. Other tests, such as root electrolyte leakage, have also shown some potential as measures of seedling physiological quality. This review identifies current methods of assessing seedling root system quality and discusses potential shortcomings of these methods. An increased understanding of the suitability of current tests, coupled with the development of new tests and multiple parameter relationships, may foster the development of species and site-specific targets for seedling root system quality assessment. The production of seedlings with root systems that meet high morphological and physiological standards better enables seedlings to rapidly establish and thrive upon outplanting. 相似文献
14.
The cutting seedlings ofLiriodendron chinense xtulipifera were treated with the different concentrations of auxin (treatment1: IBA of 50 g·kg−1+NAA of 300 g·kg−1; treatment2; IBA of 100 g·kg−1+NAA of 300 g·kg−1). The biomass nutrient element contents for different organs (root, stem, leaf) of cutting seedling ofLiriodendron chinense xtulipifera were measured by the dry method, Kjeldahl method and Atomic Absorption Spectroscopy method. The result showed that the biomass
of root, stem, and leaf of the cutting seedling treated with auxin was all remarkably increased. The contents of element C
in root, stem and leaf had no significant difference between the control and auxin treatments, while the contents of N, P,
K and Ca in stem were much lower than that in leaf and root. Variance analysis showed that for the same organ with different
concentration treatment of auxin, the four nutrient elements (N, P, K, and Ca) had no significant difference in contents,
while there existed significant or very significant difference in contents of the four nutrient elements in different organs
with the same concentration auxin treatment. The N, P, K and Ca contents were very low in cutting seedlings; as a result,
additional fertilizer should be applied to the seedlings when they were planted in the field.
Foundation item: This paper was supported by Jiangsu Province Science Foundation (BE96350).
Biography: ZHANG Xiao-ping, (1972-), female, Ph. Doctor in Nanjing Forestry University. Nanjing 210037, P. R. China.
Responsible editor: Zhu Hong 相似文献
15.
[目的]建立蒙古沙冬青子叶节丛生芽再生体系。[方法]以蒙古沙冬青子叶节为外植体,研究种子萌发培养基中6-BA浓度、子叶节萌发天数、丛生芽诱导的基本培养基及6-BA浓度对丛生芽诱导的影响和外源激素对丛生芽伸长及生根的影响。[结果]表明:(1)添加6-BA的萌发培养基与不添加的相比能够显著促进子叶节的生长及子叶节丛生芽的诱导,且6-BA浓度在2.0 mg·L-1时,诱导率最高可达73.3%,平均芽数2.26个;(2)种子萌发天数对子叶节丛生芽的诱导有显著影响,萌发7 d的子叶节丛生芽诱导率最高,诱导率为74.7%,但与萌发9、11 d的子叶节丛生芽诱导率差异不显著;(3)MS和B5培养基对丛生芽诱导的影响差异不显著,但B5抑制褐化的效果显著好于MS;(4)采用1.0 mg·L-16-BA+0.3 mg·L-1IAA激素组合有利于丛生芽伸长,伸长率为60.5%;(5)不同浓度生长素组合均能促进丛生芽幼苗生根,1.0 mg·L-1IBA生根率最大,生根数最多。[结论]最佳蒙古沙冬青子叶节丛生芽再生体系为:以在MS+2.0 mg·L-16-BA培养基中黑暗培养7 11 d的幼苗子叶节为外植体,在B5+1.0mg·L-16-BA培养基中诱导丛生芽,待丛生芽长约0.3 0.5 cm后,转入B5+1.0 mg·L-16-BA+0.3 mg·L-1IAA培养基中进行伸长培养,当丛生芽伸长至2 3 cm时,单株切下转入1/2 B5+1.0 mg·L-1IBA培养基中生根,该体系与愈伤组织培养相比能缩短培养时间,改善褐化严重、玻璃化等问题,可为蒙古沙冬青的扩繁及进一步开展遗传转化奠定基础。 相似文献
16.
[目的]研究缓释肥N/P养分配比及加载量对南方红豆杉、浙江楠和浙江樟苗木生长发育的影响,以科学指导大规格容器苗的高效培育。[方法]试验采用析因设计,研究N/P养分配比(1.75∶1、2.25∶1、2.75∶1和3.25∶1)及其加载量(1.5 kg·m~(-3)、2.5 kg·m~(-3)、3.5 kg·m~(-3)和4.5 kg·m~(-3))对3种珍贵树种2年生容器苗生长、株高生长节律、干物质积累及叶片SPAD值等影响。[结果]缓释肥N/P养分配比及加载量对3个树种容器苗生长及SPAD值影响不一。南方红豆杉、浙江楠和浙江樟干物质积累及根冠比在不同N/P养分配比间差异不大,浙江樟苗木生长受N/P养分配比影响较小,随着N/P养分配比增加,明显促进了浙江楠容器苗生长,却抑制了南方红豆杉的生长。缓释肥加载量对3个树种2年生容器苗生长和干物质积累的影响均达到极显著水平,随着缓释肥加载量增加可明显地促进3种树种株高、地径生长及干物质积累,增加了浙江楠地上干物质积累及南方红豆杉地下干物质积累,而对浙江樟根冠比影响未达统计学显著水平,但均显示加载量在3.5 kg·m~(-3)时达到最大值。N/P养分配比及与加载量的互作对3个树种苗木生长和干物质积累影响不明显,说明N/P养分配比对3个树种容器苗生长和质量的影响不因加载量的改变而变化或变化不大,反之亦然。随着缓释肥N/P养分配比的增加,可明显地延长南方红豆杉苗木株高的线性生长期,提高浙江楠株高的线性生长量,但对浙江樟株高的线性生长影响不明显。3种树种苗木叶片SPAD值差异很大,N/P养分配比及加载量并未改变3种树种叶片SPAD值动态变化规律,但随着N/P养分配比提高使南方红豆杉和浙江樟叶片SPAD值的起伏强度增大,3个树种SPAD值动态变化均随加载量增加而增大。[结论]南方红豆杉大规格容器苗培育较适宜的N/P养分配比为A1(1.75∶1)或A2(2.25∶1),而浙江楠和浙江樟为A3(2.75∶1),加载较高量的缓释肥F3(3.5 kg·m~(-3))可明显促进3种树种大规格容器苗的生长及SPAD值的提高,但加载量超过一定限度后,反而影响苗木的生长发育。 相似文献
17.
Fertilizer-induced Changes in Rhizosphere Electrical Conductivity: Relation to Forest Tree Seedling Root System Growth and Function 总被引：1，自引：0，他引：1
Fertilization is standard practice in forest tree seedling nursery culture. Additionally, fertilization at outplanting has potential to facilitate nutrient uptake and reduce transplant shock. Fertilization, however, may dramatically alter rhizosphere chemical properties such as pH, ion availability, and electrical conductivity (EC). These changes may inhibit root system growth and function by reducing soil osmotic potential and creating specific ion toxicities. The risk of root damage associated with high EC levels appears to be dependent on species, age of root system, and soil moisture availability. Root inhibition in container nursery culture of conifers is likely to occur above 2.5 dS m−1, though threshold EC levels for bareroot culture and field plantings are largely unavailable. Fertilization at outplanting has the added risk that drought conditions may prevent leaching of excess fertilizer salts, which can increase rhizosphere EC beyond safe levels and ultimately impair root uptake of water or nutrients. For fertilization programs to be successful, a critical threshold balance must be maintained between optimizing seedling nutrient availability in the rhizosphere, while minimizing potential for root damage. Future research is needed to identify optimal EC levels for a range of species across all stages of the reforestation process, from nursery culture through plantation establishment. 相似文献
18.
[Objective]A greenhouse pot experiment was conducted to evaluate the potential of Rhus chinensis Mill for phytoremediation of lead-contaminated soil.[Method]The response of container seedlings to Pb concentrations (0, 400 and 1 000 mg·kg-1) in the soil was studied. Seedling growth, chlorophyll, carotenoid, chlorophyll fluorescence, malondialdehyde (MDA), nutrient elements, Pb accumulation and translocation were assessed.[Result]The results showed that R. chinensis did not show visual symptoms of Pb toxicity. Compared to the control, the biomass increased slightly at low concentration (400 mg·kg-1). Under Pb stress conditions, the root elongation was restrained, while the radial growth of root was promoted and the fine root was developed better. No differences were observed in photosynthetic pigments, chlorophyll fluorescence, and MDA. During the experiment, only small quantity of Pb were uptake by R. chinensis, and most of the Pb absorbed by plants was retained in the roots. However, at the high concentration (1 000 mg·kg-1), R. chinensis transported metal to the shoots better, and the translocation factor (TF) value was 0.66. Under the Pb stress, oxalic acid of root exudates was increased significantly; while the root could be induced malic acid and citric acid, and the concentration increased with Pb concentration in soil. [Conclusion]R. chinensis was found to have Pb tolerance and phytoremediation potential in Pb-contaminated soils. 相似文献
19.
We tested the effects of exponential nutrient loading and springtime carbon loading during nursery culture on the field performance
of black spruce (Picea mariana (Mill.) B.S.P.). Seedlings were grown from seed with a conventional, fixed dose fertilizer (10 mg N seedling−1) or an exponential nutrient loading regime (75 mg N seedling−1). The following spring, seedlings were exposed for two weeks to either ambient (370 ppm) or elevated levels of CO2 (800 ppm) and then planted in the field; seedling growth was followed for the next six years. Exponential nutrient loading
increased seedling height, stem diameter and leader growth, with the largest increases in height and leader length occurring
in the first three years after outplanting. Carbon loading increased seedling height and leader length, but only in seedlings
that had been exponentially nutrient loaded. A combination of carbon and nutrient loading increased shoot height 26%, stem
diameter 37% and leader length 40% over trees that received neither treatment. These results demonstrate that the growth enhancement
seen under exponential nutrient loading is maintained under field conditions for at least six years. Carbon loading just before
outplanting was a useful supplement to nutrient loading, but was ineffective in the absence of nutrient loading. 相似文献
20.
[目的]针对油橄榄容器苗存在主根较为粗大、须根极少、根系盘绕等现象开展化学制剂控根试验,找出适宜油橄榄容器苗的化学控根试剂,从而解决根系畸形导致的油橄榄苗木质量差等问题。[方法]采用4种不同浓度的CuSO_4制剂及ZnSO_4制剂对油橄榄2年生容器苗进行控根试验,测定苗高、地径及地上部、下部生物量,通过根系扫描仪分析根系生长特点,探讨各项生长指标以及生理指标对控根效果的影响。[结果]显示:(1)20 g·L~(-1)和60 g·L~(-1)的Cu制剂可提高容器苗的地上部分生长量;60 g·L~(-1)和200 g·L~(-1)的Cu制剂可显著增加生物量的积累。(2)200 g·L~(-1)的Cu制剂对苗木新根着生效果最为显著;120 g·L~(-1)的Cu制剂对根系的直径、表面积和体积有良好的促进作用;而不同ZnSO_4控根制剂处理对苗木侧根的各指标产生抑制作用。(3)枝条生长量与侧根长度呈显著正相关性;地径、枝条生长量与侧根表面积呈极显著正相关关系。(4)120 g·L~(-1)的Cu制剂处理后叶片的可溶性蛋白质含量最高,Cu制剂浓度为20 g·L~(-1)时,叶片的叶绿素含量增加。[结论]试验发现质量浓度为120 g·L~(-1)和200g·L~(-1)CuSO_4制剂控根效果良好,可运用于实际生产。 相似文献