氮素形态配比对莴笋品质和养分含量的影响

Effect of Nitrogen Forms on Quality and Nutrient Content of Lettuce

采用营养液培养方法研究氮素形态配比对莴笋产量和品质及养分含量的影响。结果表明:不同处理降低莴笋产量4.5%～13.2%,降低莴笋根重29.8%～48.2%,处理6除外;处理2和处理3莴笋VC含量提高15.6%～16.2%,,处理2增加莴笋可溶性糖含量14.0%,处理4降低莴笋氨基酸含量24.0%;不同氮素形态配比处理均降低莴笋硝酸盐含量达7.5%～42.0%,降低营养中硝态氮比例,增加铵态氮或者酰胺态氮比例提高莴笋全氮含量,对全磷和全钾含量影响不一致。综合分析表明,处理2(NH_4^+:NO_3^-=2(Cl):8)为最佳处理。

The effect of nitrogen forms on quality and nutrient content of lettuce were studied using method of hydroponic culture.The results showed that biomass of lettuce were decreased by 4.5%～13.2%and the root weight were significantly decreased by 29.8%～48.2%except in NH_4~＋NO_3^- =2（S）＋2（Cl）：6 treatment.The VC content of lettuce were increased by 15.6%～16.2%in NH_4~＋-N：NO_3^--N=2 = 8 treatments and decreased by 11.8%in NH_4~＋： NO_3^- =2（S）＋2（Cl）：6 treatment.The soluble sugar content of lettuce was increased by 14.0%in NH_4~＋：NO_3^- =2（S）： 8 treatment and amino acid content was decreased by 24.0%in NH_4~＋ - NH_2：NO_3~ =2（S）：4：4 treatment.The nitrate content of lettuce were decreased by 7.5%～42.0%.The total N content of lettuce was increased with decreasing nitrate-N,increasing ammonium-N or amide-N,which had different effects on the content of total P and total K in lettuce.Taking yield and quality into consideration,the optimum treatment was NH_4~＋：NO_3^- =2（Cl）：8 for higher yield and better quality of lettuce.