摘要: |
通过研究不同氮磷钾养分水平添加对罗汉松(Podocarpus macrophyllus)土壤微生物量和多样性及其对碳源利用的变化特征,揭示罗汉松土壤微生物对不同氮磷钾养分水平的响应及规律,从微生物的角度为罗汉松施肥及管护提供理论依据。以两年生罗汉松幼苗为试验树种,采用L9正交试验控制盆栽土壤的氮磷钾养分水平梯度,使用稀释平板涂布法和Biolog-ECO微平板法探讨不同土壤养分水平对罗汉松土壤微生物量和群落多样性及其对6种碳源的利用特征。结果表明:(1)随氮添加量的增加,土壤细菌( P < 0.05)和放线菌数量( P < 0.001)减少,真菌( P < 0.001)及固氮菌数量( P < 0.01)显著增加,土壤微生物群落的Pielou index( P < 0.001)降低,Simpson index( P < 0.05)和McIntosh index( P < 0.001)升高,从而降低了土壤微生物对6种碳源的利用强度,特别是对难利用碳源胺类( P < 0.001)、羧酸( P < 0.001)、聚合物( P < 0.001)及其他化合物( P < 0.001)的利用强度显著降低。(2)磷添加量的增加显著降低了土壤微生物群落的Shannon index( P < 0.05)。(3)钾添加量的增加显著降低了土壤微生物群落的Shannon index( P < 0.05)和Pielou index( P < 0.05)及微生物群落对碳水化合物( P < 0.001)和氨基酸( P < 0.01)两类易利用碳源的利用强度。氮添加和钾添加是影响罗汉松土壤微生物群落功能多样性的主要因素,在罗汉松培育时应注意少量多次施肥,降低氮和钾的添加量,适当提高磷添加量,以促进罗汉松的生长及其可持续培育。 |
关键词: L9正交试验 Biolog-ECO 施肥 碳源利用 微生物群落功能多样性 |
DOI: |
分类号: |
基金项目:国家自然科学基金(31560061) |
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Effect of nitrogen, phosphorus and potassium additions on the functional diversity of soil microorganisms in Podocarpus macrophyllus |
Ting Lin1, Lijun Zhao1, Liqiong Zhu1, Xiangling Huang1, Guoyu Wei2
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1.College of Forestry,Guangxi University;2.Guangxi state-owned Pai Yangshan forest farm,Chong Zuo
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Abstract: |
The purpose of this study was to characterize the changes in soil microbial abundance and diversity and carbon utilization of P. macrophyllus (Podocarpus macrophyllus) by adding different levels of nitrogen(N), phosphorus(P) and potassium(K), to reveal the response of P. macrophyllus soil microorganisms to different nutrient levels of N, P andK and to provide theoretical basis for fertilization and management of P. macrophyllus from the perspective of microorganisms. In this study, two-year old P. macrophyllus seedlings were used as the test species, and the gradient of soil nutrient levels of nitrogen, phosphorus and potassium was controlled by potting method. The dilution plate coating method and Biolog-ECO microplate method were used to explore the effects of different soil nutrient levels on the amount and community diversity of P. macrophyllus soil microorganisms and their utilization characteristics of six carbon sources. The results were as follows: (1) The number of soil bacteria( P < 0.05) and actinomycetes( P < 0.001) decreased and the number of fungi( P < 0.001) and nitrogen-fixing bacteria( P < 0.01) increased significantly with the increase of N addition. The Pielou index( P < 0.001) of soil microbial community decreased and Simpson index( P < 0.05) and McIntosh index( P < 0.001) increased, thus reducing the intensity of utilization of six carbon sources by soil microorganisms, especially the intensity of utilization of difficult carbon sources, amines( P < 0.001), carboxylic acids( P < 0.001), polymers( P < 0.001) and other compounds( P < 0.001), significantly. (2) P addition significantly reduced the Shannon index( P < 0.05) of the soil microbial community, (3) K addition significantly reduced the Shannon index( P < 0.05) and Pielou index( P < 0.05) of the soil microbial community and the intensity of utilization of the two easily available carbon sources, carbohydrates( P < 0.001) and amino acids( P < 0.01), by the microbial community. In conclusion, N addition and K addition are the main factors affecting the functional diversity of soil microbial communities in P. macrophyllus. Care should be taken to apply fertilizer in small amounts and multiple times, reduce the addition of N and K, and increase the addition of P appropriately to promote the growth of P. macrophyllus and its sustainable cultivation. |
Key words: L9 orthogonal test Biolog-ECO Fertilization carbon source utilization microbial community functional diversity |