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福建5种类型茶园土壤硝化作用及其影响因子

Nitrification of Five Types of Soils at Tea Plantations in Fujian

  • 摘要: 通过室内培养试验(土壤最大持水量60%和温度28℃),研究了福建省5种类型(黄壤、红壤、潮砂土、高山草甸土和紫色土)茶园土壤硝化作用,并探讨了影响土壤硝化作用的关键土壤因子。结果表明,5种茶园土壤NO3-N含量随时间的变化呈“J”型增长趋势,具有3~7 d的延滞期,符合指数方程N=N0ektp<0.01);茶园土壤净硝化量N)、硝化强度(Nt)、硝化率(Nr)和硝化常数(k)分别为7.70~98.23 mg·kg-1、0.22~2.81 mg·kg-1·d-1、55.41%~95.67%和0.151~0.328 mg·kg-1·d-1,高山草甸土和黄壤茶园NNtNr显著高于其它土壤类型(p<0.05),潮砂土和紫色土次之,红壤最低;培养结束后,茶园土壤pH值下降了0.11~0.30个单位,酸化明显。相关分析结果表明,茶园土壤硝化势(N0)、NNr均与土壤有机碳、全氮和NO3-N之间呈显著或极显著正相关,与土壤容重呈显著或极显著负相关,与土壤C/N、pH、砂粒和粉粒相关性不显著。以上结果说明,研究中5种茶园土壤硝化作用较强,均存在硝化作用延滞期(3~7d),土壤有机碳、全氮、NO3-N和土壤容重是影响酸性茶园土壤硝化作用的主要因素。(

     

    Abstract: A lab experimentation on soil nitrification was conducted on 5 types of tea plantation soils, including yellow, red, moist sandy, alpine meadow and purple soils, found in Fujian. The tests were carried out at 28℃ with the soil samples maintained at a maximum moisture holding capacity of 60%. Factors affecting the nitrification were analyzed to show the following results. (1)The nitrate content in the soil changed with time in a “J” shaped curvature; i.e., after an initial stagnation during 3~7 d, an exponential function followed: N=N0ektp<0.01).(2)The net nitrified nitrogen(N), nitrifying capacity(Nt), nitrification ratio(Nr)and k value of the soil samples ranged from 7.70~98.23 mg·kg-1, 0.22~2.81 mg·kg-1·d-1, 55.41~95.67% and 0.151~0.328 mg·kg-1·d-1, respectively.(3)N, Nt and Nr in the alpine meadow and yellow soils were significantly higher than those in the others(p<0.05); and, they were followed by those in the moist sandy and purple soils, while those in the red soil being the lowest of all.(4)At the end of the test, the soil pH declined 0.11~0.30. And,(5)Nitrification potential(N0),N and Nr either significantly or very significantly correlated with the organic carbon, total N, and NO3-N in the soil, and either significantly or very significantly correlated negatively with the soil bulk density; but not significantly correlated withIt appeared that these 5 acidic soils from the tea plantations had a high nitrification activity after initial 3~7 d, and that the organic carbon, total N, NO3-N and bulk density of the soil could be considered the critical factors controlling the nitrification in the soils. C/N, pH value, sand or silt in the soil.

     

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