不同氮处理下增施CO2对番茄叶片养分含量的影响

为探究不同氮处理对番茄植株叶片养分的影响及增施CO2的效果。以番茄"鸿途"为试验材料,在2个自然光照人工气候室内,采用苗钵基质栽培,设置5个氮素处理的营养液(50、150、250、350、450 mg·L^-1,分别设为N1~N5)、2个CO2浓度(300、600μL·L^-1,分别设为C1、C2),分别测定植株开花期、坐果期、果实膨大期生物量及叶片硝态氮和矿质元素含量。结果表明:中氮处理(N 250~350 mg·L^-1)下,植株干质量、叶片硝态氮含量以及矿质元素N、P、K、Ca、Mg含量均较高。增施CO2处理后,番茄植株干质量较C1处理增加了10.2%,叶片N、K、Mg含量都增加了20%左右,P含量没有变化,Ca含量降低了25.67%;低氮处理(N 50 mg·L^-1)下,番茄植株干质量、叶片硝态氮含量以及矿质元素N、P、K、Mg、Ca含量均较对照N3处理低。增施CO2处理后,植株的总干质量没有显著增加,其叶片硝态氮含量以及N、P、K含量也没有显著变化,而Ca含量在开花期和坐果期较C1处理分别增加了37.72%、15.45%,Mg含量在开花期较C1处理增加了43.86%;高氮处理(N 450 mg·L^-1)下,植株干质量较N3处理降低了18.03%,叶片硝态氮含量较N3处理增加了111.44%,叶片N、Ca、Mg含量与N3处理接近均较高,P、K含量较N3处理均降低了10%。增施CO2处理后,植株干质量较C1处理增加了35.92%,叶片硝态氮含量增加不显著,叶片N、K、Mg含量较C1处理分别增加了19.06%、27.82%、24.87%,而叶片P含量变化不显著,叶片钙含量在番茄开花期、坐果期和果实膨大期都较低,较C1处理分别降低了21.37%、17.16%、7.75%。综合番茄生长各项指标及经济效益,在营养液N浓度为250~350 mg·L^-1时,增施CO2浓度到600μL·L^-1(C2)最能促进开花期番茄植株叶片养分含量的增加。

Effect of CO2 Supplementation on Nutrient Content in Tomato Leaves at Different Nitrogen Treatments

To explore the effect of different nitrogen treatmenton the nutrient of tomato leaves and the effect of CO2 supplementation.Tomato variety of ‘Hongtu’ was cultured in two artificial climate room under natural light in the pot with substrate.Five nutrient solutions of different nitrogen treatment were adopted(50,150,250,350,450 mg·L^-1,respectively was N1-N5),and two CO2 concentrations were setted up(300,600 μL·L^-1,respectively were C1,C2).The whole plant biomass,the contents of nitrate nitrogen and mineral elements in leaves were determined at the stage of plant flowering,fruit setting,fruit enlargement,respectively.The results showed that under the medium N level(N 250-350 mg·L^-1),the total dry weight and the contents of nitrate nitrogen and mineral elements N,P,K,Ca and Mg of the leaves were higher.After supplemented CO2,the dry weight of tomato plants was increased by 10.2% compared with the control(C1).The contents of N,K and Mg in the leaves were increased by about 20%,while the content of P was unchanged,and the Ca content was decreased by 25.67%;under low N level(N 50 mg·L^-1),the plant dry weight and the contents of nitrate nitrogen and mineral elements N,P,K,Ca and Mg were lower than those of N3 treatment.After supplemented CO2 treatment,the total dry weight of plant was no significant change,and the contents of the nitrate nitrogen and N,P,K were no significant change,but the contents of Ca at flowering period and fruit setting period were increased by 37.72% and 15.45% compared with the control(C1),respectively,the content of Mg at flowering period was increased by 43.86% than C1 treatment;under the high N level(N 450 mg·L^-1),the plant dry weight was lower by 18.03% than N3 treatment,nitrate nitrogen content in the leaf was increased by 111.44% than N3 treatment,and the contents of N,Ca,Mg in leaf closed to that of N3 treatment,were both higher,the contents both of P and K reduced by 10% than N3 treatment.After supplemented CO2,the plant dry weight increased by 35.92% than the control,and the content of nitrate nitrogen in the leaves was no significant increase,the contents of N,K,Mg were increased by 19.06%,27.82% and 24.87% than C1 treatment,respectively.However,the P contents in the leaves was no significant change,the Ca contents in the leaves at the stage of tomato flowering period,fruit setting and fruit enlargement period were lower compared with C1 treatment,were reduced by 21.37%,17.16% and 7.75%,respectively.Comprehensive the growth indicators and economic benefit,the nutrient contents oftomato leaves during flowering period were increased,in the condition of nutrient solution N concentration of 250 mg·L^-1(N3)-350 mg·L^-1(N4),and elevated CO2 concentration to 600μL·L^-1(C2).