摘要
采用田间试验研究了双氰胺(dicyandiamide,缩写DCD)单次配施和连续配施的土壤氮素形态和蔬菜硝酸盐累积变化。结果表明,与单施化肥相比,DCD单次配施的长期叶菜甘蓝生长过程中土壤铵态氮含量增幅为21.3%—339.4%,土壤硝态氮和菜体硝酸盐含量降幅分别为5.4%—80.2%和4.4%—58.3%;短期叶菜空心菜收获时土壤铵态氮含量增加了299.4%,土壤硝态氮和菜体硝酸盐含量分别降低了26.2%和31.7%。DCD连续配施的"甘蓝-菠菜-空心菜-萝卜-大白菜"种植体系中,土壤铵态氮、硝态氮和菜体硝酸盐含量均呈累积的趋势,配施DCD的土壤铵态氮含量从略高于化肥处理(44.0%)发展到极显著高于化肥处理(392.5%,P<0.01),土壤硝态氮含量从极显著低于化肥处理(-68.2%,P<0.01)发展到显著高于化肥处理(146.6%,P<0.05),菜体硝酸盐含量从显著低于化肥处理(-30.2%,P<0.05)发展到极显著高于化肥处理(40.4%,P<0.01)。由此可见,DCD单次配施可显著降低菜体硝酸盐含量,而连续配施DCD的土壤能维持一定量的铵态氮水平,这些盈余的铵态氮会进一步转化为硝态氮残留在土壤中,并可能产生蔬菜硝酸盐累积的风险。
Dicyandiamide （DCD） is one of the quality and inexpensive, environmentally friendly nitrification inhibitors, but long-term field experiments were not completed. In order to evaluate the environmental effects of DCD on farmland, researches on long-term application of DCD is extremely required. Application of DCD could increase soil NH4＋-N, and decrease soil NO3--N contents. However, the changes of NH4＋-N and NO3--N in soil and the nitrate in vegetable when DCD single fertilized is consistent with those in multiple application of DCD are not clearly known. Therefore, three field trials were adopted to comprehensively investigate the changes of soil nitrogen types and nitrate accumulation in vegetables, comprising two treatments and each treatment was replicated three times. Two trials with single application of DCD were located in Putian City（latitude 25°25＇06″ N, longitude 119°01＇54″ E）, the long-term leafy cabbage and short-term leafy spinach were planted from 28 November 2009 to 27 March 2010, and 21 June to 24 July 2011, respectively. The experiment with successive cropping of vegetables was carried out at the Experimental Station of Fujian Farmland Conservation, Ministry of Agriculture, in Baisha Town, Fuzhou City（latitude 26°12＇33″ N, longitude 119°04＇52″ E）, the vegetables such as cabbage, spinach, water spinach, radish, Chinese cabbage were cultivated in sequence from 4 December 2008 to 27 April 2011. In comparison to chemical fertilizer application alone （control）, in the growth process of cabbage, single application of DCD, soil NH4＋-N increased from 21.3 to 339.4%, NO3--N in soils and in vegetables decreased from 5.4 to 80.2% and from 4.4 to 58.3%, respectively. In the harvest time of spinach, when DCD was single applied, soil NH4＋-N increased about 299.4%, soil NO3--N decreased about 26.2%, NO3--N in vegetables decreased about 31.7%, respectively. However, in the ＂cabbage-spinach-water spinach-radish-Chinese cabbage＂ successive cropping system, soil NH4�
出处
《生态学报》
CAS
CSCD
北大核心
2013年第15期4608-4615,共8页
Acta Ecologica Sinica
基金
国家科技支撑计划课题(2012BAD14B15)
福建省省属公益类科研院所基本科研专项(2011R1024-5)
福建省财政专项福建省农业科学院科技创新团队建设基金(STIF-Y01)
关键词
双氰胺
单次配施
连续配施
氮素形态
硝酸盐累积
dicyandiamide（DCD）
single application
muhiple application
nitrogen types
nitrate accumulation
