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对大花序桉幼苗生物量及营养元素进行测定,结果表明,大花序桉苗木平均单株生物量大小排序为茎>根>叶。幼苗主要营养含量和吸收积累规律为K>N>P>Fe>Mn>Zn>B>Ca>Cu>Mg。大量元素N、P、K贮量最高的部位均为茎,根部和叶中含量相近。大花序桉苗期叶片对主要营养元素N、P和K的吸收分配间存在相互促进的关系;Mg与Ca,Cu与P、K,Zn与N、K、Cu、Fe,Fe与N呈现互相促进关系;Mn与N、Fe、K、Cu,B与P、Cu为相互抑制关系。据此,大花序桉苗期以氮、磷、钾肥为主,其中要求养分K2O>N>P2O5,并有针对性地添加铁肥、锌肥和铜肥。 相似文献
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[目的]为认识马尾松细根对土壤养分库的贡献,[方法]本研究以三峡库区秭归县九岭头林场马尾松为研究对象,采用埋袋法进行细根分解实验,探讨0.5 mm、0.5 1 mm和1 2 mm细根的分解动态和养分释放(C、N、P、K、Ca、Mg)。[结果]结果表明:(1)细根分解368 d后,0.5 mm、0.5 1 mm和1 2 mm细根干重残留率分别为66.0%、72.0%和74.33%,且细根分解速率随直径增加而减小;(2)细根分解速率与土壤温度呈显著正相关关系(p0.05),与土壤湿度呈正相关关系(p0.05);(3)细根C、K和Mg元素迁移模式表现为释放,Ca元素表现为富集;(4)细根N、P元素在不同径级细根中迁移模式不同,0.5 mm细根N、P元素表现为释放,0.5 2 mm细根N、P元素在分解过程中出现富集阶段。[结论]马尾松细根分解与土壤温度和直径大小显著相关,其中分解与温度呈正相关,与直径呈负相关;在细根分解过程中,马尾松细根不同直径大小的不同养分元素的表现状态不一致,或富集,或释放。 相似文献
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M.C. Feller 《Forest Ecology and Management》1983,7(2):77-102
The distribution and movement of N, P, K, Na, Mg, and Ca were studied in southeastern Australia in a 37—year-old Pinus radiata plantation and in a nearby Eucalyptus obliqua — Eucalyptus dives forest of the same age and of the same type as that which had been replaced by the P. radiata plantation. The soil beneath the P. radiata plantation contained significantly less total N and exchangeable K, Mg, and Ca than that beneath the eucalypt forest. No large accumulation of nutrients was found in either the litter or the trees in the P. radiata plantation relative to that in the eucalypt forest. However, there was a slightly greater accumulation of N and K in the P. radiata biomass than in the eucalypt biomass. The annual soil nutrient balance obtained by subtracting outputs (mineral soil leachate + biomass incorporation) from inputs (precipitation + mineral weathering) indicated a more favourable balance for each nutrient in the soil beneath the eucalypts than in the soil beneath the pines. Calculations suggested that these balances could only partially account for the differences in soil nutrient quantities between eucalypt and pine ecosystems. It was hypothesized that these differences are also partially explainable in terms of the nutrient losses accompanying two fires which had occurred in the pine plantation area. Nitrogen balances in this study were incomplete because several potentially important fluxes were not measured. 相似文献
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为掌握雷州半岛桉树 LH1 无性系林的土壤养分概况,探索不同整地方式对土壤养分的影响,
研究以全垦、开沟、挖穴 3 种整地方式造林,采用“5 穴综合法”进行土壤取样,分析评价了 LH1 无性
系林的土壤 pH 值、有机质、碱解 N、速效 P、有效 K 等 11 个养分指标,以及各指标与不同整地方式之
间的关系。结果表明,LH1 无性系碱解 N 较缺乏,土壤有机质,速效 P、有效 K 处于中等水平,交换性
Ca、Mg 含量皆低于临界值,微量元素 Zn 丰富,Cu、Mn 适中,B 较缺乏;不同整地方式对除土壤 pH 值
外的其它 10 种养分指标的影响显著(P<0.05),开沟方式土壤中有机质、主要营养元素 N、P、K,以及
中量元素 Ca、Mg 的含量,都要高于挖穴和全垦的整地方式,桉树经营上可以利用开沟的方式营林,以
增加土壤养分;整地方式对土壤中不同微量元素影响作用也很显著,并且在不同土层上表现不同。土壤
养分指标之间既有促进作用,也有拮抗作用,与整地方式紧密相关;生产上可以针对微量元素 B 缺乏的
现状,适量增加微量元素 Mn 或降低 Mg 来加以改善。 相似文献