摘要:
采用短期(35d)室内好气培养方法,研究福建省武夷山市5种主要茶园土壤(黄壤、红壤、潮砂土、紫色土、高山草甸土)的氮素矿化特征,并探讨土壤矿化作用与土壤理化性质之间的关系。结果表明:35d的培养试验证实茶园土壤氮矿化过程符合一级反应动力学方程Ni=N0(1-e-kt)(R2=0.65~0.98);茶园土壤潜在可矿化氮库(N0)为4.15~52.46 mg·kg-1(均值为33.22),土壤氮矿化常数k值为0.019~0.343mg·kg-1·d-1(均值为0.15),土壤氮供应综合指标(No*k)为0.32~16.82 mg·kg-1·d-1(均值为6.49),矿化率(Nr)为2.32~6.00%(均值3.73),高山草甸土和黄壤氮矿化参数均显著高于其他土壤类型,紫色土和潮砂土次之,红壤最低。相关分析表明,土壤的△N、N0和k均与土壤有机碳、全氮和矿质氮含量(NH+4-N和NO-3-N)呈显著正相关,与土壤容重呈极显著负相关(P<0.01),与C/N和pH无显著相关;土壤砂砾和粉粒含量与k和N0*k间存在显著相关,但其与其他矿化参数相关性不显著。
关键词:
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土壤类型
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茶园
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氮素矿化
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相关性
Abstract:
For this study,5types of soils at tea plantations,i.e.,yellow,red,moist sandy,alpine meadow and purple soils,collected from Wuyishan City in Fujian were incubated at 28℃with a 60% water holding capacity for 35 days.The nitrogen(N)mineralization and its correlation with the properties of the soils were analyzed.A firstorder kinetic model derived from the experimental data was obtained:Ni=N0(1-e-kt)(R2=0.65-0.98),where Niis the cumulative mineralized N at incubation time t;N0,the potential mineralizable N pool;and k,the first order rate constant.N0 for the soils ranged from 4.15 to 52.46mg·kg-1(averaging 33.22mg·kg-1);kfrom0.019 to 0.343mg·kg-1·d-1(averaging 0.15mg·kg-1·d-1);N0×kfrom 0.32 to 16.82 mg·kg-1·d-1(averaging 33.22mg·kg-1·d-1);and the N mineralization rate(Nr)from 2.32 to 6.00%(averaging 3.73%).All parameters of the N mineralization in the alpine meadow and yellow soils were significantly higher than those in the others.They were followed by the moist sandy and purple soils,while the red soil was the lowest.△N,N0,k and N0×k were significantly correlated with the soil organic carbon,as well as the total N,NH+4-N and NO-3N.They also significantly correlated reversely with the soil bulk density,but not significant correlated with C/N or pH.The sand and silt contents in the soil significantly correlated with kand N0×k,but not with other indicators.
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