Fall fertilization enhanced nitrogen storage and translocation in Larix olgensis seedlings
Fall fertilization enhanced nitrogen storage and translocation in Larix olgensis seedlings
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DOI：
10.1007/s11056-013-9370-z
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发表时间：
2013-06
期刊：
影响因子：
2.2
通讯作者：
Y. Zhu;R. K. Dumroese;J. R. Pinto;G. Li;Y. Liu
中科院分区：
文献类型：
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作者：
Y. Zhu;R. K. Dumroese;J. R. Pinto;G. Li;Y. Liu
落叶林苗木的秋季养分负荷由于叶片脱落和不同的转运模式而受到特别关注。对于苗圃中不落叶的幼苗，秋季施肥通常可以逆转养分稀释，并可能增加养分储备；然而，这种技术在落叶针叶树中很少受到关注，落叶针叶树在叶子脱落之前转运营养物质。研究了秋季氮肥施肥对落叶针叶林奥尔加湾落叶松（Larix olgensisHenry）幼苗硬化期氮素储存和转运的影响。幼苗在25 mg N - 1中处理15周，然后进行硬化和秋季施肥处理，分别在0、5、10和15 mg N - 1中施用k15no3，为期3周。在硬化期，秋季施氮对幼苗形态影响不大。随着针叶脱落，针叶的氮浓度和含量急剧下降，而茎和根的氮浓度和含量则增加。在停止施肥6周后，所有的幼苗从针叶中转移了相似的净氮。对于对照苗，这占茎和根中储存氮的84%。然而，对于秋季施肥的幼苗，由于秋季肥料的吸收直接转运到茎和根，从针叶转运的茎和根中储存的氮只占总量的41 - 61%。在秋季施肥6周后，幼苗内氮浓度和含量的分布规律为：茎b>细根>粗根>针叶。我们的研究结果表明，在落叶针叶树幼苗的硬化过程中提供氮，以奥尔加湾落叶松为例，是促进苗圃生产过程中养分负荷的一种方式。
Fall nutrient loading of deciduous forest nursery seedlings is of special interest because of foliage abscission and varied translocation patterns. For non-deciduous seedlings in the nursery, fall fertilization typically can reverse nutrient dilution and possibly increase nutrient reserves; however, this technique has received little attention with deciduous conifer trees that translocate nutrients before abscising foliage. We evaluated how fall nitrogen (N) fertilization affected N storage and translocation in the deciduous conifer Olga Bay larch (Larix olgensisHenry) seedlings during the hardening period. Seedlings were supplied with 25 mg N seedling−1for 15 weeks before hardening and fall fertilization treatments began with a three week application period of K15NO3at 0, 5, 10 and 15 mg N seedling−1. During the hardening period, fall N fertilization had little effect on seedling morphology. The N concentration and content of needles decreased dramatically as needles abscised, while that of stems and roots increased. Six weeks after fall N fertilization ceased, all seedlings translocated similar net N from their needles. For the control seedlings, this accounted for 84 % of the N stored in stems and roots. For fall fertilized seedlings, however, the proportion of N stored in stems and roots translocated from needles accounted for only 41–61 % of the total because of absorption of fall fertilizer that was translocated directly to stems and roots. Six weeks after fall fertilization, the distribution pattern of N concentration and content in seedlings was found in this order: stems > fine roots > coarse roots > needles. Our results suggest that providing deciduous conifer seedlings N during hardening, in this case Olga Bay larch, is a way to promote nutrient loading during nursery production.