金堂环溪河流域土壤氮素含量及其影响因素分析

Analysis on Soil Nitrogen Content and Influence Factors in Jintang County of the Huanxi River Valley

采集耕层(0～20cm)土样108个,研究其氮素含量及其影响因素。结果表明,研究区土壤全氮和碱解氮均呈正态分布。其中土壤全氮平均含量为0.52g kg-1,碱解氮平均含量为68.1mg kg-1。地形条件、土地利用方式和轮作制度是影响土壤氮素含量的重要因素。统计分析表明,不同台位之间土壤全氮含量均未达到显著水平;不同台位之间土壤碱解氮含量差异显著,冲沟水田(77.1mg kg-1)、一台地(72.3mg kg-1)和二台地(71.0mg kg-1)均显著高于丘顶地(51.6mg kg-1)。四种土地利用方式之间全氮含量呈显著差异,林地(0.69g kg-1)和旱地(0.45g kg-1)、水田(0.48g kg-1)分别达到极显著差异和显著差异水平,非林地之间差异不显著;四种土地利用方式之间碱解氮含量呈极显著差异,林地(81.3mg kg-1)与旱地(56.1mg kg-1)达到极显著差异,而在非林地之间,旱地与果园(77.2mg kg-1)、水田(70.8mg kg-1)分别达到显著差异。轮作制度对土壤氮素含量和分布的影响程度不如台位和土地利用方式,四种轮作制度之间土壤全氮和碱解氮含量均未达到显著差异。

Jintang County of the Huanxi River Valley is one of chief cash crop zones in Sichuan basin.The nitrogen contents in topsoil（0～20cm）and influence factors were conducted.The results were as follows：Total N and Available N contents were lower,avaragely were 0.52g kg^-1 and 68.14mg kg^-1.Distrbution types of tofal N and available N were both normal.The factors which influenced soil nitrogen content included the topography,land use types and Planting systems.Between different slopes in the hills,total N content did not differ significantly.Between different slopes in the hills,available N content differed significantly at P〈0.5,Available N content differed significantly with the paddy field（77.1mg kg^-1）,the valley field（72.3mg kg^-1）,the middle field（71.0mg kg^-1） and the top hill（51.6mg kg^-1）at p〈0.05,while available N content did not differ significantly among the middle field,the valley field and the paddy field.Between different land use types,total N content differed significantly at p〈0.05.Total N content differed significantly with forestry（0.69g kg^-1）and dry land at P〈0.01 and with forestry and paddy at P〈0.05.Between different land use types,available N content differed significantly at P〈0.01.Available N content differed significantly with forestry（81.3mg kg^-1）and dry land（56.1mg kg^-1）at P〈0.01 and with orchard（77.2mg kg^-1） and paddy（70.8mg kg^-1） at P〈0.05.Between different rotating systems,total N and available N contents did not differ significantly.