槟榔间作香露兜模式下土壤微生物区系分析

Effect of Areca catechu L.intercropping with Pandanus amaryllifolius Roxb.on soil microflora

【目的】土壤微生物区系是表征土壤健康的重要指标,从土壤微生物群落结构与多样性角度评价不同种植模式对热区农田土壤健康的影响,为优化槟榔林下间作香露兜模式提供理论依据与数据支撑。【方法】采用大田试验方法,设置槟榔单作(DB)、香露兜单作(DX)和槟榔间作香露兜(JZ)3种种植模式,研究不同种植模式下土壤微生物区系变化,分析土壤理化性质、养分含量等指标与土壤微生物群落结构之间的关系,探究槟榔间作香露兜模式驱动土壤微生物群落演替的主要因子。【结果】槟榔间作香露兜对真菌群落的影响较小,却显著改变土壤细菌群落组成与多样性指数。槟榔间作香露兜显著提高土壤细菌丰富度与多样性指数,所有土壤样品中的细菌群落优势菌群均为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)和厚壁菌门(Firmicutes),其相对多度分别为22.59%、19.60%、16.66%和16.11%。尽管间作模式不改变细菌群落多度,却相比于槟榔单作显著提高酸杆菌门细菌多度75.09%,同时降低厚壁菌门细菌多度75.42%。相关性分析与RDA分析结果共同表明土壤细菌丰富度与多样性指数主要受土壤速效氮、磷、钾含量以及土壤pH的影响;Spearman等级相关分析表明土壤养分含量变化是驱动酸杆菌门和厚壁菌门细菌演替的主要因子。【结论】间作模式通过显著降低土壤速效磷、速效钾和碱解氮等养分含量以及提高土壤pH抑制土壤细菌群落丰富度与多样性指数,并通过降低土壤养分水平显著提高酸杆菌门物种多度,同时降低厚壁菌门物种多度,进而显著改变土壤区系结构。槟榔林间作香露兜能够显著改善槟榔单作土壤微生物区系,有助于槟榔仅土壤健康保育及相关产业可持续发展。

【Objective】 Soil microflora is an important indicator for characterizing the soil health. The objective of this study is to clarify the effects of different planting patterns on the structure and diversity of soil microbial communities i.e soil health in tropical areas, so as to provide theoretical basis and data support for optimizing the intercropping mode of Areca catechu L. and Pandanus amaryllifolius Roxb. 【Method】Three planting modes: A.catechu L. Mono-cropping(DB), Areca catechu L. intercropping P.amaryllifolius Roxb.(JZ) and P.amaryllifolius Roxb. mono-cropping(DX) were set up under a field experiment to analysis the changes of microbial communities under different planting modes in this study. The relationships between the soil physical, nutrient content and other indicators and chemical characteristics and microbial communities were analyzed to explore the main factors driving the succession of soil microbial community in intercropping model.【Result】 Intercropping mode did not affect fungal community, but significantly changed the structure and diversity of soil bacterial community. Intercropping mode significantly increased the richness and diversityindex of soil bacteria. The dominant phyla of bacterial in the soil samples among all treatments were Proteobacteria, Acidobacteria, Actinobacteria and Firmicutes with abundances of 22.59%, 19.60%, 16.66% and 16.11%, respectively. Compared with A.catechu L. mono-cropping, intercropping mode significantly increased the abundance of Acidobacteria and decreased the abundance of Firmicutes by 75.09% and 75.42%, respectively. The correlation analysis and RDA analysis indicated that the richness and diversity index of soil bacteria were mainly affected by the contents of soil available nitrogen, phosphorus, potassium and pH. Spearman’s rank correlation coefficients showed that the soil bacterial diversity was mainly affected by the soil nutrient content. 【Conclusion】The richness and diversity index of soil bacterial community was inhibited by intercropping significantly by reducing soil available phosphorus, available potassium and available nitrogen content, and increasing soil pH. The soil nutrient content was decreased by intercropping, which significantly increased the species abundance of Acidobacteria, and decreased the species abundance of the Firmicutes. The intercropping mode could significantly improve the soil microflora of A.catechu L. mono-cropping. Intercropping will conducive to maintain soil health and sustainable development of related industries.