烟稻轮作中稻草还田对土壤有机氮各组分的影响

Effects of Rice-straw-returning Under Tobacco-rice Rotation on Soil Organic Nitrogen Fractions

以湘南烟区常年稻草还田与否的14个不同土样为研究对象,根据Keeney和Bremner土壤有机氮分级方法,研究湘南烟区烟稻轮作中稻草还田对土壤有机氮各组分含量及组成的影响。结果表明:稻草还田主要是提高了土壤有机氮组分中酸解未知态氮含量,而非土壤铵态氮、氨基酸态氮和酸不溶性氮含量差异的主导因素。稻草还田加强了铵态氮、酸解未知态氮和酸不溶性氮与有机质、全氮和碱解氮三者之间的相关性;减弱了氨基酸态氮、氨基糖态氮与有机质、全氮、碱解氮之间的相关性。

14 different soils under tobacco-rice rotation in southern Hunan Province were collected to study the effects of rice-straw-returning on the contents and components of organic nitrogen fractions in soils based on Keeney and Bremner＇s classification of organic nitrogen.The results showed rice-straw-returning only increased the content of unknown hydrolysable nitrogen rather than the contents of ammonia nitrogen,amino acid nitrogen and unhydrolysable nitrogen;Rice-straw-returning enhanced the correlations between ammonia nitrogen,unknown hydrolysable nitrogen,unhydrolysable nitrogen and organic matter,total nitrogen,alkali-hydrolyzable nitrogen,while weakened the correlations between amino acid nitrogen,amino sugar nitrogen and organic matter,total nitrogen,alkali-hydrolyzable nitrogen.