【作者】 张永起； 李淑仪； 廖新荣； 蓝佩玲； 王荣萍； 邵鹏；

【机构】 中国科学院广州地球化学研究所； 广东省生态环境与土壤研究所； 中国科学院研究生院；

【摘要】 本文依托测土配方施肥田间试验的数据,开展露地蔬菜土壤供氮指标研究,旨为华南菜田土壤养分丰缺指标体系建设提供参考。以蔬菜不施氮肥处理与完全施肥处理的相对产量的50%、75%、90%和95%为指标,建立华南菜田土壤碱解氮丰缺指标,根据土壤碱解氮含量划分的极缺、缺、中等、高和极高5级水平的土壤供氮指标分别为小于30、30～90、90～170、170～210和大于210mg kg^-1。针对目前逐渐采用土壤硝态氮作为土壤供氮指标的需求,建立了碱解氮-硝态氮和碱解氮-无机氮的转换方程,分别为:y_硝态氮=0.3894x_碱解氮-1.4103和y_无机氮=0.4838x_碱解氮+2.0328,二者均达到极显著水平。由该方程计算得出,当蔬菜相对产量为50%、75%、90%和95%时,并对所建立的丰缺指标进行不同形态氮的指标值转换。土壤硝态氮的丰缺指标转换值为:11mg kg^-1、34mgkg^-1、66mg kg^-1和82mg kg^-1;无机氮的丰缺指标转换值为:17mg kg^-1、46mg kg^-1、86mgkg^-1和105mg kg^-1。更多还原

【Abstract】 This paper was aimed to introduce our investigative study on establishing soil alkali hydrolysable N abundance and deficiency indices of vegetable-producing areas in southern China.In addition,inorganic N and dissociative NO^3--N were also transformed to abundance and deficiency index values.For this purpose,experiments of soil testing and fertilizer recommendation were conducted in vegetable-producing areas of southern China during 2007 to 2009.Soil alkali hydrolysable N were classified as very low（<50%relative yield ）,low（50%～75%relative yield ）,medium（75%～90% relative yield ）,high（90%～95%relative yield ） and very high（>95%relative yield ） based on the relative yields.Abundance and deficiency indices of soil alkali hydrolysable N were simulated by the models of logarithmic equation.The results indicated that soil alkali hydrolysable N indices were<30mg·kg^-1,30～90 mg·kg^-1,90～170mg·kg^-1,170～210mg·kg^-1,and>210 mg·kg^-1 when soil fertility were classified as very low,low,medium,high and very high,respectively.Meanwhile,conversion model of alkali hydrolysable N to dissociative NO₃^- is stimulated by liner equation,it was y = 0.3894x -1.4103; alkali hydrolysable N to inorganic N is also stimulated by liner equation,which was y = 0.4838x + 2.0328,both of them shown strong significant correlations.Transformed by these models,abundance and deficiency index values of dissociative NO₃^- were:<11mg·kg^-1,11～34mg·kg^-1,34～66mg·kg^-1, 66～82mg·kg^-1 and>82mg·kg（-1）;abundance and deficiency index values of inorganic N were:<17mg·kg^-1,17～46mg·kg^-1,46～86mg·kg^-1,86～105 mg·kg^-1 and>105mg·kg^-1,respectively,when soil fertility are classified as very low,low,medium,high and very high.更多还原