不同氮磷钾水平对水培生菜产量和品质的影响

摘要

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 re-spectively, measuring the yield and the contents Vet.C, nitrate, soluble sugar and soluble protein of let-tuce 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 in-creased 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.