低硝酸盐叶菜水培营养液配方优选

为研究叶菜中硝酸盐含量高的问题，利用营养液膜栽培技术(NFT)，采用不同营养液配方对不同种类叶菜的产量及品质进行测试。结果表明：配方3(Mg2 含量最高)营养液培育的生菜产量最高，产量可达17556 kg/hm2.茬，较其他2种配方相对增产率分别为133.3%、171.42%。配方3培育的生菜根体积、叶绿素含量、总鲜重、叶片数、植株干重等指标明显优于其他配方。通过测试品质指标，得知配方3营养液培育的生菜硝酸盐含量最低，为745.46 mg/kg，分别较配方1（K 含量最高）、配方2（Ca2 含量最高）降低77.01%、79.78%。配方3营养液培育的生菜Vc含量最高，分别较其他2种配方提高22.36%、78%，且糖酸比明显提高，有效提高了生菜的品质。综合品质指标、生物学指标及产量测定结果，得出配方3营养液最适合培育生菜、油菜、油麦菜等叶菜，为优选出的最佳叶菜水培营养液配方。

Optimum Formula of Hydroponic Nutrient Solution for Low Nitrate Leaf Vegetables

To solve the problem of high nitrate content in leaf vegetables, this research used NFT (nutrient film technique) and different nutrient solution formula, to test yield and quality of different kinds of leaf vegetables. The results showed that lettuce yield was the highest by using the nutrient solution formula 3 (with the highest content of Mg2 +), the yield of each harvest could reach 17556 kg/hm2,the increase rate reached 133.3% and 171.42% compared with that of the other two formula, respectively. The root volume, content of chlorophyll, total fresh weight, leaf number, and plant dry weight of lettuce cultured with formula 3 were better than those of the other two formula. Quality testing results showed that nitrate content of lettuce was the lowest by using nutrient solution formula 3 (745.46 mg/kg), and the nitrate content of lettuce was reduced by 77.01% and 79.78% respectively compared with that of the other two formula (with the highest content of K + and Ca2 + , respectively). The Vc content of lettuce was the highest by using nutrient solution formula 3, which was 22.36%and 78% higher than those by using the other two formula, respectively, and the sugar acid ratio increased significantly which could improve the quality of lettuce effectively. Considering the results of quality indicators, biological indicators and yield, formula 3 is most suitable for cultivating leaf vegetables such as lettuce, rapeseed and leaf lettuce, it is the optimum hydroponic nutrient solution formula for leaf vegetables.