Effects of rice-straw-returning under tobacco-rice rotation on soil organic nitrogen fractions
烟稻轮作中稻草还田对土壤有机氮各组分的影响

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 bet...