槟榔间作香露兜对土壤微生物丰度与多样性的影响

研究槟榔林下间作香露兜对土壤微生物群落丰度及多样性的影响,不仅为维护热区农田土壤健康提供理论依据,还为优化槟榔林下间作香露兜模式提供数据支撑。本研究采用大田试验的方法,选择万宁、琼海和陵水3个地区建立试验样地,每个试验样地分别设置槟榔单作、香露兜单作和槟榔间作香露兜3种种植模式,测定土壤理化性质、养分含量、土壤微生物丰度与多样性等指标,以槟榔和香露兜单作为对照,探究槟榔间作香露兜模式对土壤微生物群落结构的影响。槟榔间作香露兜模式下真菌丰度显著提高,但多样性没有变化,而间作模式下土壤细菌丰度显著低于香露兜单作和槟榔单作;不同地区试验样地的真菌丰度与多样性不存在差异,但细菌丰度与多样性差异显著;土壤细菌丰度和多样性指数与土壤pH、速效钾、土壤容重以及有机质含量之间存在显著正相关关系,与土壤含水量之间呈显著负相关关系。本研究中,槟榔间作香露兜模式通过降低土壤有机质和速效钾等养分含量,抑制土壤细菌群落丰度与多样性。在不同地区或种植模式下,维持较高的土壤养分水平有助于保持土壤微生物群落结构相对稳定以及维护土壤健康。

Effect of Areca catechu L.Intercropping Pandanus amaryllifolius Roxb.on Soil Microbial Diversity and Richness

Areca catechu L. is an important tropical cash crop in Hainan Province. Developing Areca catechu L. understory economy is very important for the sustainable development of agriculture. Pandanus amaryllifolius Roxb. is a perennial tropical spice plant, which is shade resistant and suitable for intercropping under Areca catechu L. forest. The aim of this study is to explore the effects of Areca catechu L. and Pandanus amaryllifolius Roxb. on the abundance and diversity of soil microbial communities. By clarifying the differences in the structure and diversity of microbial communities under different planting patterns and their key driving factors, reveal the physical and chemical properties of the soil and the internal relationship between the microenvironment and the structure of the microbial community. This study would provide a theoretical basis for maintaining the soil health of Areca catechu L. forest, and provide a theoretical basis for elucidating the dynamic balance mechanism of soil microbial community under Areca catechu L. intercropping Pandanus amaryllifolius Roxb. model, also provide data support for optimizing the intercropping Pandanus amaryllifolius Roxb. model under Areca catechu L. forest. A randomized block design was adopted in this experiment. Field experiments were established with Areca catechu L. mono-cropping, Areca catechu L. intercropping Pandanus amaryllifolius Roxb. and Pandanus amaryllifolius Roxb. mono-cropping, respectively. The field experiments were repeated three times in Wanning, Qionghai and Lingshui, Hainan Province. The soil physical and chemical properties, nutrient content, soil microbial abundance and diversity were measured to explore the effect of intercropping model on soil microbial community structure. The abundance of soil bacteria in the intercropping were significantly lower than those in the mono-cropping treatments. The fungal abundance rather than diversity increased significantly in intercropping. There was no significant difference in fungal abundance and diversity index among different regions. The abundance and diversity of bacteria varied significantly among the three study plots. There was a significant positive correlation between bacterial abundance and diversity and soil bulk density, organic matter content and soil pH. However, bacterial abundance and diversity were significant negative correlation with water content. The intercropping model significantly inhibited the abundance and diversity of soil bacterial community by reducing the contents of soil organic matter and available potassium in this study. Soil organic matter, available potassium, soil bulk density and pH are the key factors driving the change of soil. In the intercropping mode, appropriate supplement of organic and potassium fertilizer was contributed to maintain the relative stability of soil microbial community structure and soil health.