不同氮磷钾水平对水培生菜产量和品质的影响

Effects of different N,P and K concentration on yield and quality of hydroponic lettuce

为了研究氮磷钾对水培生菜(Lactuck sativa L.var.ramosa Hort.)产量和品质的影响,分别对氮磷钾设置5个浓度梯度,在收获时测定生菜的产量和维生素C、硝酸盐、可溶性糖以及可溶性蛋白等品质指标.结果发现,随着氮素水平从3.0 mmol/L增加到9.0 mmol/L,生菜的产量、维生素C、硝酸盐、可溶性糖以及可溶性蛋白都呈现出先增大后减小的趋势;磷素水平从0.2 mmol/L增加到1.0 mmol/L,生菜的产量和硝酸盐先增大后减小,可溶性糖和可溶性蛋白逐渐增大,维生素C逐渐减少;钾素水平从2.0 mmol/L增加到6.0 mmol/L,生菜的产量和硝酸盐先增大后减小,可溶性糖、可溶性蛋白、维生素C均有逐步增大的趋势.当氮磷钾浓度分别为7.76、0.69和3.86 mmol/L时可获得高产目标,当氮磷钾浓度分别为4.0、0.4或0.6和4.0 mmol/L,可获得优质目标.

In order to study the effects of N, P and K concentration on yield and quality of hydroponic lettuce （Lactuck sativa L. var. ramosa Hort. ） , five concentration gradients of N, P and K were set respectively, measuring the yield and the contents Vet. C, nitrate, soluble sugar and soluble protein of lettuce at harvest time, the results showed that as the nitrogen level increased from 3.0 mmol/L to 9.0 mmoL/L, the yield and the contents Vet. C, nitrate, soluble sugar and soluble protein of lettuce increased first then decreased; as the phosphorus level increased from 0. 2 mmol/L to 1.0 mmol/L, the yield and nitrate content of lettuce increased first and then decreased, soluble sugar and soluble protein contents increased gradually, the Vet. C content reduced gradually; as the potassium level increased from 2.0 mmol/L to 6. 0 mmol/L, the yield and nitrate content of lettuce increased first then decreased, soluble sugar, soluble protein and Vet. C contents showed a tendency to increase. When the concentration of N, P and K were 7.76, 0. 69 and 3.86 mmol/L respectively, the high yield target could be obtained, and when the concentration of N, P and K were 4. 0, 0.4 or 0. 6, and 4.0 mmol/L respectively, good quality target could be achieved.