凤庆县不同古茶园根际与非根际土壤酶活性及其化学计量特征

Enzyme activities and stoichiometric characteristics of rhizometric and non-rhizosphere soil in different ancient tea gardens in Fengqing County,China

研究不同古茶园土壤养分状况间的差异影响,可为古茶园的土壤养分管理提供理论依据,实现茶园的提质增效.以凤庆县郭大寨乡3个典型古茶园的根际与非根际土壤为研究对象,探究其根际与非根际土壤理化性质、土壤酶活性及其化学计量比之间的关系.结果显示:(1)茶园根际与非根际土壤养分含量及酶活性差异显著(P<0.05),且表现出不同的土壤营养条件.(2)不同茶园的根际土壤含水量、全碳、全氮、全磷含量差异显著(P<0.05),均表现为大箐>龙潭>琼英;同时,龙潭茶园土壤pH=4.5为茶树生长最适值.(3)不同茶园非根际土壤胞外酶活性的高低表现为大箐>龙潭>琼英,其活性与土壤含水量、全碳、全氮、全磷含量正相关,其中土壤含水量解释了97.2%变异,与pH值负相关.而在植物根系的作用下,根际土壤酶活性呈现出不同变化趋势;其活性与土壤含水量、pH值、全碳、全氮、全磷含量均正相关,土壤含水量解释了93.9%的变异,全碳解释了5.2%的变异.(4)根据土壤酶化学计量比矢量分析,3个茶园土壤微生物受碳源限制程度不同,限制程度为琼英>龙潭>大箐,大箐茶园土壤微生物受到一定程度的磷限制(Vector A>45°),龙潭和琼英茶园受到轻微的氮限制(Vector A<45°).综上,本研究表明不同坡向茶园土壤养分、含水量和pH差异显著.综合3个茶园的土壤指标变化,大箐、龙潭茶园更有利于古茶树的生长,建议对琼英茶园进行合理的灌溉、深耕及施用无机肥,改善茶树根际土壤状况.本研究可为当地古茶园及古茶树保护利用提供理论参考.

This study aimed to reveal the effects of soil nutrient status on ancient tea gardens.This can provide a theoretical basis for soil nutrient management in ancient tea gardens and help improve the quality and efficiency of tea gardens.The rhizosphere and non-rhizosphere soils of three typical ancient tea gardens in Guodazhai Township,Fengqing County,China were taken as research objects.The relationships among the physicochemical properties,soil enzyme activities,and stoichiometry ratio of the rhizosphere and nonrhizosphere soils were explored.The results showed that(1)there were significant differences in nutrient content and enzyme activity between the rhizosphere and non-rhizosphere soils in tea gardens(P<0.05),and different soil nutrient conditions were exhibited.(2)There were significant differences in the rhizosphere soil water content,total carbon,total nitrogen,and total phosphorus content in the different tea gardens(P<0.05),all of which manifested in the order Daqing>Longtan>Qiongying.The soil pH=4.5 in Longtan tea garden was the optimal value for tea plant growth.(3)The activity of extracellular enzymes in the non-rhizosphere soil of different tea gardens was in the order Daqing>Longtan>Qiongying,and its activity was positively correlated with soil water content,total carbon,total nitrogen,and total phosphorus content,among which the soil water content explained 97.2%of the variation.Soil extracellular enzyme activity was negatively correlated with pH.Under the action of plant roots,the enzyme activity of rhizosphere soil showed different trends.Activity was positively correlated with soil water content,pH,total carbon,total nitrogen,and total phosphorus content.Soil water content explained 93.9%of the variation,while total carbon explained 5.2%.(4)According to the soil enzyme stoichiometric ratio vector analysis,the soil microorganisms in the three tea gardens were limited to different degrees by the carbon source,and the degree of restriction was Qiongying>Longtan>Daqing.Soil microorganisms were limited by phosphorus to a certain extent(Vector A 45°)in Daqing tea gardens,and Longtan and Qiongying tea gardens were slightly limited by nitrogen(Vector A 45°).In summary,the results showed that soil nutrients,water content,and pH differed significantly among tea gardens with different slopes.Based on the changes in the soil indices of the three tea gardens,the Daqing and Longtan tea gardens were conducive to the growth of ancient tea plants.Qiongying tea gardens should carry out reasonable irrigation,deep plowing,and inorganic fertilizer application to improve rhizosphere soil conditions.These results provide a theoretical reference for the protection and utilization of ancient local tea gardens and tea trees.