不同种植年限水田与旱地土壤有机氮组分变化  

FRACTIONS OF SOIL ORGANIC NITROGEN IN PADDY AND UPLAND SOILS RELATIVE TO CROPPING HISTORY

作　　者：王晋[1] 庄舜尧[1] 朱兆良[1] 

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008

出　　处：《土壤学报》2014年第2期286-294,共9页Acta Pedologica Sinica

基　　金：中德科学中心资助项目(GZ518)资助

摘　　要：在浙江慈溪地区，由于不同时期围海造田形成了具有长时间尺度序列的典型水稻土和旱地土壤，为研究长期的土壤氮素生物地球化学循环过程提供了很好的对象。本研究运用封管水解Bremner法测定了不同种植年限下土壤氨基酸氮、氨基糖氮、氨态氮、未知氮等酸解性有机氮组分，以探究不同种植年限和种植方式对土壤有机氮组分的影响。结果显示，旱地土壤的不同氮组分含量仅为水稻土相对应氮组分含量的50%~60%，水稻种植较旱地更利于土壤氮素的保存和利用。从长时间尺度来看，除氨基酸氮和水稻土氨基糖氮外，有机氮各组分含量随时间呈指数变化趋势，水稻土主要呈增加趋势，而旱地土壤则表现为降低趋势。该地区土壤氨基酸氮占全氮比例为23.5%~29.3%，氨基糖氮比例为6.0%~7.6%，氨态氮为21.0%~28.8%，未知氮为13.0%~21.1%，不同种植方式和种植年限对土壤主要有机氮组分所占全氮比例影响不大。In Cixi of Zhejiang Province, as a result of poldering in different time periods a long time scale succession of paddy soils and upland soils formed, which could be cited as good objects for the study of long term biogeochemical cycle of soil nitrogen. In order to explore effects of cropping history and pattern on soil organic nitrogen fractions, amino acid N, amino sugar N, NH3 – N and hydrolyzable unknown N in the soils were analyzed with the Bremner method through hydrolysis in sealed tubes. Results show that the content of any fraction of organic nitrogen in the upland soil was only 50% ~ 60% of that of its counterpart in the paddy soil, suggesting that rice planting is more conducive to conservation and utilization of the soil organic nitrogen. On a long-time scale, all the organic nitrogen fractions, except amino acid N and amino sugar N, varied with the time exponentially, showing that organic nitrogen in the paddy soils was mainly on a rising trend, while that in the upland soils on a reverse one. In the soils of this area, amino acid N accounted for 23.5% ~ 29.3%, amino sugar N for 6.0% ~ 7.6%, NH3 – N for 21.0% ~ 28.8%, and hydrolysable unknown N for 13.0% ~ 21.1% of the total nitrogen, indicating that cropping pattern and cropping duration neither has much effect on proportions of the major soil organic nitrogen fractions to the total nitrogen in the soils.

关 键 词：水稻土 旱地土壤 种植年限 有机氮 

分 类 号：S158[农业科学—土壤学]