夜间增温对免耕农田土壤氮矿化与硝化速率的影响  

Effect of no-tillage and nighttime warming condition on N mineralization and nitrification rates in cropland soil

作　　者：李旸[1] 刘尔宁 董京铭 张耀鸿[1] 罗雪顶 杨世琼[1] 刘凤凤[1] 吴雪亚 

机构地区：[1]南京信息工程大学,气象灾害预报预警与评估协同创新中心,江苏省农业气象重点实验室,江苏南京210044 [2]江苏省连云港市气象局,江苏连云港222000

出　　处：《中国土壤与肥料》2016年第4期54-58,69,共6页Soil and Fertilizer Sciences in China

基　　金：国家自然科学基金青年基金项目(41103039);江苏省大学生创新创业训练计划项目(201410300008Z);江苏省农业气象重点实验室开放课题项目(KYQ1307)

摘　　要：研究了农田土壤氮矿化速率和硝化速率对长期夜间增温和免耕的响应特征。试验设置4种处理：常温＋翻耕（CK）、夜间增温＋翻耕（W）、常温＋免耕（NT）、夜间增温＋免耕（WNT）。与对照相比,W处理下土壤中碱解氮和铵态氮明显增加,其中1-2月增幅分别为26%-28%和82%-133%,且土壤氮矿化速率和硝化速率均显著高于CK处理。NT处理下,土壤碱解氮和铵态氮的季节均值分别提高了15%和41%;土壤氮总矿化速率显著高于CK和W处理,硝化速率则显著低于CK和W处理。WNT处理下的土壤氮矿化速率显著高于NT处理,而硝化速率则显著低于CK和W处理,可见,在夜间增温条件下,采取免耕措施将有利于土壤有机氮的矿化过程,降低了土壤硝化速率,从而减小了土壤氮素损失的风险。Open field nighttime warming system was designed to investigate the effects of long-term nighttime warming and successive no-tillage on inorganic nitrogen（ N） and mineralization and nitrification rates in the cropland soil. The experiments were conducted with four treatments： normal nighttime temperature with traditional tillage（ CK）,nighttime warming with traditional tillage（ W）,normal nighttime temperature with no-tillage（ NT）,and nighttime warming with no-tillage（ WNT）. Compared to CK,alkali-hydrolyzable N and ammonium N remarkably increased under W treatment,which were increased by 26%-28% and 82%-133%,respectively in January and February. In the incubation experiments,mineralization and nitrification rates increased significantly in warming treatments. Under NT treatment,soil average alkali-hydrolyzable N and ammonium N contents were increased by 15% and 41%,respectively than those of CK,while mineralization rate was significantly highter and nitrification rate was significantly lower in NT than those in CK and W treatments. For WNT treatment,mineralization rate was higher than that in NT treatment,nitrification rate was lower than those in CK and W treatments. Thus,it was concluded that no-tillage could facilitate mineralization process of organic N in cropland soil,inhibit nitrification process,and hence reduce the risk of N loss.

关 键 词：夜间增温 免耕 有机氮矿化速率 土壤硝化速率 

分 类 号：S153.6[农业科学—土壤学]