不同植茶年限土壤氮素组分变化及其与环境因子关系

Changes in Soil Nitrogen Components and Their Relationship with Environmental Factors with Different Tea Plantation Ages

茶园土壤氮素组分变化影响茶园土壤供氮能力和氮素循环.以植茶30、 50和70 a的茶园土壤为研究对象,探讨不同植茶年限土壤氮素组分变化特征及其与理化性质和酶活性之间的关系.结果表明:(1)随着植茶年限的增加,粉粒、全磷、脲酶和过氧化氢酶活性逐渐增加,砂粒、黏粒、 pH、电导率、有机碳和蔗糖酶活性逐渐降低,碱性磷酸酶活性先增加后降低,土壤含水量和酸性磷酸酶活性无显著变化.(2)随着植茶年限的增加,酸解性铵态氮、氨基酸态氮和硝态氮含量显著增加,且茶园土壤全氮、酸解性铵态氮、未知态氮和非酸解氮含量显著高于林地.(3)全磷、碱性磷酸酶和脲酶是土壤氮素组分变化的主要影响因子.其中,有机氮组分与全磷、碱性磷酸酶活性具有显著相关性,无机氮组分与碱性磷酸酶活性具有显著相关性,全氮与砂粒、粉粒、全磷、脲酶和碱性磷酸酶活性具有极显著的相关性.

Changes in soil nitrogen components in tea gardens affect the soil nitrogen supply capacity and nitrogen cycle.In this study,soil samples were collected from forest land,cultivated land,and tea gardens with different plantation ages(30,50,and 70 years)to explore the changes in soil nitrogen components and their relationship with physicochemical properties and enzyme activities.The results showed that:①with the increase in tea plantation age,the silt,total phosphorus,and urease and catalase activities gradually increased,whereas the sand,clay,pH,electrical conductivity,soil organic carbon,and the activities of invertase gradually decreased.The alkaline phosphatase activity increased first and then decreased with the increase in tea plantation age,and no significant differences were observed in soil water content and acid phosphatase activity.②With the increase in tea plantation age,the contents of acid ammonia nitrogen,amino acid nitrogen,and nitrate nitrogen(NO_(3)^(−)-N)increased significantly,and the contents of total nitrogen,acid ammonia nitrogen,hydrolyzable unknown nitrogen,and non-hydrolyzable nitrogen in tea gardens were significantly higher than those in forest land.③The total phosphorus,alkaline phosphatase,and urease were the main factors affecting soil nitrogen components.Among them,organic nitrogen components were significantly correlated with total phosphorus and alkaline phosphatase,and inorganic nitrogen components were significantly correlated with alkaline phosphatase,whereas total nitrogen had significant correlations with sand,silt,total phosphorus,urease,and alkaline phosphatase.