【摘 要】
：
目前，银杏（Ginkgo biloba L．）的价值正在被人们逐步地认识，尤其是银杏叶提取物的药用价值，在预防和治疗心脑血管疾病等方面表现出了神奇的效果。现在研究表明，银杏叶中主要的药效成
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目前，银杏（Ginkgo biloba L．）的价值正在被人们逐步地认识，尤其是银杏叶提取物的药用价值，在预防和治疗心脑血管疾病等方面表现出了神奇的效果。现在研究表明，银杏叶中主要的药效成分是黄酮类物质和萜内酯类物质。由于这两种物质在银杏体内的合成机理还不十分清楚，还不能够对其合成进行调控，只能通过种植、栽培、加强肥水管理等外部因素增加其含量。 本文研究了不同用量的腐植酸复合肥及等养分的无机肥料对银杏生长、黄酮含量及土壤微生物数量的影响。结果表明： 1 施肥能够显著提高银杏叶有效成分黄酮的含量，黄酮含量与腐植酸复合肥的不同用量间呈显著二次曲线相关，回归方程为yHAF=8.1527+0.0245x-0.00006x2，R=0.9788。在投入养分量相等的情况下，腐植酸复合肥处理银杏叶黄酮含量比无机肥处理平均提高了5.5％，并且在第二施肥水平下差异显著。 2 施肥对提高银杏叶绿素含量有显著促进作用，叶绿素含量与腐植酸复合肥和无机肥料用量均呈显著二次曲线相关。腐植酸复合肥处理与等养分无机肥料相比，叶绿素a含量平均提高了11.4％，叶绿素b含量平均提高了11.9％，叶绿素总量平均提高了11.5％。并且银杏叶绿素a／b值随着腐植酸复合肥和无机肥料用量的增加，均表现出先降后增的趋势。综合黄酮含量与叶绿素含量的分析结果，得出此银杏地的最佳腐植酸复合肥的养分用量为200 kg·hm-2。 3 腐植酸复合肥能够活化土壤中的磷素，显著提高土壤中速效磷的含量，最高的土壤速效磷含量是对照的3.76倍，而无机肥处理与对照间相比，土壤速效磷含量没有显著差异。等养分处理下，施用腐植酸复合肥的土壤速效磷含量，均显著高于施用无机肥的处理，并且腐植酸复合肥还能显著提高银杏叶片中全磷的浓度。由此可得出腐植酸复合肥能显著提高磷肥的利用率。 4 腐植酸复合肥能够显著增加土壤微生物的数量，对不同种类的微生物影响效果不同：对细菌的影响最大，真菌次之，对放线菌的影响效果最小。土壤中真菌数量与土壤中速效氮、磷、钾含量呈极显著正相关；细菌数量与土壤速效氮、磷含量呈极显著正相关，与速效钾含量呈显著正相关；放线菌只与速效氮、钾含量呈显著正相关。 5 腐植酸复合肥能有效地改善银杏叶缘黄化现象。银杏生长的中后期，对照和无机肥最高用量的小区，银杏树出现了较严重的叶缘黄化现象，甚至有的银杏叶出现焦枯、坏死现象。而腐植酸复合肥处理的小区，银杏叶黄化现象明显较轻，腐植酸复合肥第二、第三施肥水平处理只有个别的银杏树出现了叶缘黄化现象。
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