滴灌施氮对番茄氮代谢及水氮利用的影响

Effects of Drip Irrigation with Nitrogen Fertigation on Tomato Nitrogen Metabolism and the Use of Water and Nitrogen

为探究滴灌施氮对番茄氮代谢的影响及适宜水氮供应模式,开展了3种滴灌方式(常规滴灌CDI、固定滴灌FDI和交替滴灌ADI)和3种施氮水平对番茄氮代谢和水氮利用影响的盆栽试验。与CDI相比,N_(80)(N肥用量为0.16 g/kg土)下,ADI保持番茄叶片游离氨基酸含量与硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性,果实成熟期叶片硝态氮和可溶性蛋白质含量分别提高16.4%和16.1%;N_(80)下ADI和FDI保持水分利用效率(WUE)、氮肥偏生产力和番茄干物质量。各施氮水平间比较,ADI下番茄叶片NR和GS活性、WUE、地上部干物质量和总干物质量以N_(80)最高。总干物质量与叶片可溶性蛋白质含量、NR和GS活性关联度较高。因此,ADI-N_(80),即交替滴灌-N_(80)既有利于改善番茄氮代谢,又保持了番茄WUE、氮肥偏生产力和干物质量,为最适宜水氮供应模式。

In order to study the effect of drip irrigation with nitrogen fertigation on tomato nitrogen metabolism and optimal water and nitrogen(N)supply mode,a pot experiment was conducted to investigate the effects of 3 drip irrigation methods(conventional drip irrigation CDI,fixed partial root-zone drip irrigation FDI,alternate partial root-zone drip irrigation ADI)and 3 N fertilization levels on tomato nitrogen metabolism,water and N use.The results showed that:compared to CDI,ADI maintained leaf soluble protein content,NR and GS activity,increased NO_(3)^(-)-N and soluble protein by 16.4% and 16.1% at N_(80)(applied with N of 0.16 g/kg soil);ADI and FDI maintained tomato water use efficiency(WUE),nitrogen partial productivity and dry mass accumulation at N_(80).In comparison of the 3 N fertilization levels,under ADI,N_(80) had the highest NR,GS,WUE,shoot dry mass and total dry mass,while total dry mass had significant correlation with leaf soluble protein,NR and GS activity.Thus ADI-N_(80) is recommended as suitable water and N supply mode for maintain tomato water use efficiency,nitrogen partial productivity,dry mass accumulation and improving tomato nitrogen metabolism.