预培养温度对稻田土壤氮素矿化影响  

Effect of pre-incubated temperature on soil organic nitrogen mineralization in paddy field

作　　者：彭显龙[1,2] 刘春艳[1] 马昕[1] 梁辰[1] 于刚[3] 于彩莲[4] 

机构地区：[1]东北农业大学资源与环境学院,哈尔滨150030 [2]黑龙江省粮食产能协同创新中心,哈尔滨150030 [3]黑龙江八一农垦大学经济管理学院,黑龙江大庆163319 [4]哈尔滨理工大学化学与环境工程学院,哈尔滨150040

出　　处：《东北农业大学学报》2016年第4期49-56,共8页Journal of Northeast Agricultural University

基　　金：国家自然科学基金项目(41101281)

摘　　要：为明确预培养温度对氮素矿化影响,选择南北方典型稻田土壤,经12、25和35℃预培养2周后,与风干土一起恒温培养28 d(25℃),测定培养前后铵态氮含量,分析预培养过程中土壤有机氮组分变化。结果表明,随预培养温度升高,初始铵态氮含量逐渐增加,矿化氮含量逐渐减少,当预培养温度为35℃时,矿化氮含量甚至降为负值。虽然12和25℃预培养不会影响土壤总矿化氮含量,但模型拟合显示,风干土矿化过程与经预培养的土壤矿化过程明显不同。风干土直接培养2周或经25℃预培养2周后,可酸解氮含量均有所增加,难酸解氮含量明显降低;与风干土相比,12℃预培养有机氮组分变化不明显;而随预培养温度升高,酸解氮含量先增后减,难酸解氮先减后增。可见,难酸解氮在矿化过程中可能也发挥重要作用。35℃预培养温度会改变土壤供氮过程,12℃预培养后土壤有机氮组分变化较小,矿化过程更符合实际。因此,测定土壤氮素矿化应以12℃作为预培养条件。This study was conducted to compare the effects of 12, 25 and 35 ℃ pre-incubated on soil N mineralization, soil after pre-incubated two weeks and air-dried soil sample were incubated under 25 ℃during 28 d. Ammonium nitrogen content of soil was measured before and after incubation, the content of soil organic nitrogen components were analyzed in the process of incubation. The results showed that with the increase of pre-incubation temperature, the initial ammonium nitrogen increased, but the mineralization N rate significantly reduced. Mineralization N rate was negative or a little when the pre- incubation temperature was increased to 35 ℃. Although the 12 and 25 ℃ pre-incubation temperature did not reduce the total amount of soil mineralization nitrogen, model fitting displayed the mineralization process of air-dried soil was different from soil after pre-incubation. The content of hydrolysamino acid N was increased and the acid insoluble nitrogen in soil was decreased after air-dried soil directly cultured for two weeks or after 25 ℃pre-culture. Compared with air-dried soil, the content of organic nitrogen for 12 ℃ pre-incubation was not significantly different. With the increasing of pre-incubation temperature, the content of hydrolysamino acid N increased first and then decreased, the acid insoluble nitrogen decreased first and then increased. These results indicated that the acid insoluble nitrogen may also play an important role in the mineralization process, and the composition of organic nitrogen made a significant change when the pre- incubation temperature was higher than 25 ℃. This resulted in changing of the process of soil nitrogen mineralization process. On the contrary, the organic nitrogen forms and soil N mineralization process changed a little when pre-incubation temperature was 12 ℃. Therefore, 12 ℃ should be used as pre-incubation temperature.

关 键 词：稻田 土壤 氮素矿化 温度 有机氮 

分 类 号：S158.5[农业科学—土壤学]