不同水氮条件下双氰胺(DCD)对温室黄瓜土壤氮素损失的影响  

Effects of dicyandiamide on nitrogen loss from cucumber planting soil in intensive greenhouse under different irrigation and nitrogen conditions

作　　者：张琳[1] 孙卓玲[1] 马理 吉艳芝[1] 巨晓棠[3] 张丽娟[1] 

机构地区：[1]河北农业大学资源与环境学院,河北省农田生态环境重点实验室,河北保定071000 [2]河北省永清县蔬菜管理局,河北廊坊065600 [3]中国农业大学资源与环境学院/教育部植物-土壤相互作用重点实验室,北京100193

出　　处：《植物营养与肥料学报》2015年第1期128-137,共10页Journal of Plant Nutrition and Fertilizers

基　　金：农业部"948"项目(2012-Z36);河北省教育厅项目(Q2012130)资助

摘　　要：【目的】设施蔬菜习惯"大水大肥"的传统管理模式,不仅影响蔬菜的品质和产量,造成严重的资源浪费,而且引起的环境污染问题日益受到人们的关注。本研究针对设施蔬菜生产中过量施用氮肥以及不合理的灌溉所导致的氮肥利用率低、氮素损失等资源浪费和环境的负效应问题,重点研究双氰胺(DCD)在设施蔬菜生产体系中的硝化抑制效果及其影响机制,并筛选出了适用于设施黄瓜生产的最优水氮管理方案。【方法】采用田间原位跟踪法,对温室黄瓜追肥期间土壤N2O排放量、氨挥发损失量、无机氮含量等指标进行了测定。N2O气体样品用密闭式静态箱法采集,用Agilent GC6820气相色谱仪进行测定。氨挥发样品用密闭室法采集,硼酸溶液吸收,标准硫酸滴定法测定。新鲜土样用1.0 mol/L KCl浸提,滤液用TRACCS 2000型流动分析仪测定土壤的NH+4-N和NO-3-N含量。【结果】在不同水氮条件下[传统水氮(T)的施氮量为N 988.6 kg/hm2、灌溉量为758.8 t/hm2;推荐水氮Ⅰ(R1)的施氮量为N 709.4 kg/hm2,推荐水氮Ⅱ(R2)的施氮量为N 746.9 kg/hm2,灌溉量均为531.2 t/hm2]。加施DCD后,推荐水氮Ⅰ、推荐水氮Ⅱ处理N2O的排放通量分别显著减少了42.1%和64.1%,但氨挥发损失分别显著增加了34.3%和40.4%;0—10 cm土层土壤硝态氮与N2O排放通量呈极显著的正相关,铵态氮与氨挥发损失呈极显著正相关。传统水氮处理在0—60 cm土壤剖面均检测到大量的硝态氮,前两次追肥后尤为明显。在减氮基础上加施DCD有助于减少硝态氮的累积,对0—30 cm根区硝酸盐淋洗的抑制作用较为明显。在0—30 cm土壤-蔬菜体系中,传统水氮处理的氮素表观损失显著高于其他施氮处理。加施DCD后,推荐水氮Ⅰ、推荐水氮Ⅱ处理的氮素盈余和氮素损失率均有所降低。与传统水氮处理相比,推荐水氮Ⅱ+DCD的处理增产23.3%,经济效益增加25560yuan/hm2。【结论】在本【Objectives】The traditional management mode of greenhouse vegetables is under 'a large number of irrigation and fertilization'. This mode not only affects quality and yield of vegetables,but also causes serious wasteof resources and environmental pollution. Aiming at excessive application of nitrogen fertilizer and low nitrogen fertilizer utilization rate caused by unreasonable irrigation,nitrogen loss and other waste of resources and negative effects of environmental problems in greenhouse vegetable production were studied with focusing on nitrification inhibition effect and its mechanism of dicyandiamide( DCD) to select the best water and nitrogen management program for greenhouse cucumber production. 【Methods】A field in-situ tracking experiment was carried out to determine N2 O emission,ammonia volatilization loss,inorganic nitrogen in soil and other indicators during the greenhouse cucumber dressing. N2 O gas samples were collected by enclosed static box method,and gas samples was analyzed by gas chromatography with Agilent GC6820. Ammonia volatilization samples were collected by closed chamber method,added 20 m L 2% boric acid solution into evaporating dish of 50 m L,and after 24 hours,absorption of ammonia in boric acid was titrated with standard sulfuric acid. Fresh soil samples were extracted with1. 0 mol / L KCl,and analyzed for NH+4-N and NO-3-N using continuous flow analysis( TRAACS 2000) in laboratory. 【Results】Compared with the recommended water and nitrogen treatments ofⅠandⅡ,the applications of DCD with the recommended water and nitrogen treatments ofⅠandⅡcould reduce N2 O emission by 42. 1% and64. 1%,while the applications increase ammonia volatilization loss by 34. 3% and 40. 4% respectively. Soil NO-3-N and N2 O flux,NH+4-N and ammonia volatilization loss in 0-10 cm soil layer are positively correlated. The traditional water and nitrogen treatment has large amounts of NO-3-N in 0-60 cm soil profiles,especially after the first two dressing. Based on the reduction of nitrogen,a

关 键 词：减氮控水 N2O排放 氨挥发 无机氮 产量 经济效益 

分 类 号：S153.6[农业科学—土壤学]