连作植烟土壤酚酸类物质变化特征及其与主要环境因子的Mantel Test分析

Correlation analysis of main environmental factors and phenolic acids in continuous tobacco cropping soils using Mantel Test

为明确酚酸类物质在连作植烟土壤中的变化特征,探讨土壤主要环境因子对酚酸类物质的影响,以不同连作年限(4 a, 6 a, 8 a, 14 a和16 a)植烟土壤为对象,研究了不同连作年限植烟土壤酚酸类物质、理化性状、酶活性和细菌多样性的变化特征,并利用MantelTest分析了酚酸类物质与土壤主要环境因子的相关性。结果表明,随连作年限增加,土壤酚酸类物质和速效钾含量升高, pH、有机质含量、细菌菌群丰度和多样性降低,水解性氮和有效磷含量呈先降低后升高趋势,酶活性呈先升高后降低趋势。Mantel Test分析表明,土壤酚酸类物质含量与理化性状、酶活性和细菌丰度显著相关,且与理化性状相关性最高;不同酚酸类物质含量与土壤主要环境因子相关性存在差异,其中,对羟基苯甲酸和阔马酸与植烟土壤理化性状、酶活性以及细菌丰度的相关性最高。因此,在本试验条件下,连作植烟土壤酚酸类物质具有明显积累特征,植烟土壤环境恶化;酚酸类物质积累受理化性状、酶活性和细菌多样性影响,且理化性状影响最大;不同酚酸类物质受主要土壤环境因子的影响存在差异,其中对羟基苯甲酸和阔马酸积累所受影响最大。

Flue-cured tobacco is a crop sensitive to continuous cropping.Continuous cropping over the long-term has seriously affected growth and production quality of flue-cured tobacco by affecting the soil environment.Phenolic acids can cause growth disorders under continuous cropping.Although the interaction between phenolic acids and other environmental factors after entering the soil environ-ment has not much been investigated,it is clear that phenolic acids occur in soils under continuous tobacco cropping.The action process and the role in limiting continuous cropping are critical for successful tobacco cultivation.An experiment was conducted to determine the relationship between phenolic acids and soil environmental factors in the soil by analyzing the correlation between various environmen-tal factors and phenolic acids in soil.The purpose was to identify the environmental factors affecting the concentration of phenolic acids in soils under continuous cropping systems.Soils of four tobacco fields with different durations of continuous cropping(4 a,6 a,8 a,14 a and 16 a)were sampled.The changes in phenolic acids,physical and chemical properties,enzyme activities and bacterial diversities in soils under different continuous cropping years of tobacco were investigaed.The correlation between phenolic acids and soil envi-ronmental factors was analyzed using the Mantel Test.The results showed that long-term continuous cropping of tobacco resulted in an increase in soil phenolic acids content.Higher pH of soil under tobacco continuous cropping resulted in low soil organic matter content,but increased available potassium.The activities of catalase,urease acid phosphatase,and invertase first increased and then later de-creased.When continuous cropping for less than 6 years,bacterial community structure changed little.However,bacterial community structure changed significantly after 8 years of continuous cropping.In general,continuous cropping changed bacterial community structure and reduced community diversity.Mantel Test analysis showed that phenolic acid content was significantly correlated with enzymes activities and physical and chemical properties of soil.Bacterial abundance had the highest correlation with soil physical and chemical properties.There were differences in correlation between different phenolic acids and soil environmental factors.P-hydroxybenzoic acid and phoronic acid had the highest correlation with physical and chemical properties of soil,enzyme activity and bacterial abundance in soils.Therefore,phenolic acids in soils under continuous tobacco cropping obviously accumulated over time with deteriorated soil environment.The accumulation of phenolic acids was affected by soil physical,chemical and biological properties of soil.P-hydroxybenzoic acid and tartaric acid were two kind phenolic acids most affected.