不同营养液钾浓度对水培生菜生长、品质和营养液利用效率的影响

Effects of Different Potassium Concentrations in Nutrient Solution on Growth,Quality and Nutrient Solution Utilization Efficiency of Hydroponic Lettuce

以"富兰德里"生菜为研究对象,设置0.6 (T1)、1.5 (T2)、2.4 (T3)、3.0 (T4)和6.0 (T5) mmol/L-1共5个营养液钾浓度处理,探究不同营养液钾浓度对水培生菜的生长、产量、品质、营养液消耗及营养液利用效率的影响。结果表明:T4处理叶面积最大,比其他处理增长了9.33%-65.91%;营养液钾浓度处理对生菜叶片SPAD值影响不显著;T4处理冠部鲜质量最大,比其他处理增加了5.91%-145.82%,T3处理根部鲜质量最大,比其他处理增加了0.30%-71.88%;营养液钾浓度与生菜的可溶性糖呈负相关,对VC含量影响不显著,对生菜硝酸盐含量影响不明显;T1处理的营养液消耗量最少,比其他处理减少了16.01%-35.63%,T5处理的营养液消耗量最多,比其他处理增加了2.39%-55.48%;T1处理的营养液利用效率最低,T4处理的营养液利用效率最高,比其他处理提升了2.21%-61.89%;通过生菜产量、营养液利用效率与营养液钾浓度的关系,进行了营养液钾浓度优化,得到营养液钾浓度为3.9 mmol/L时,生菜产量最高,为142.03 g/株;营养液钾浓度为3.5 mmol/L时,生菜营养液利用效率最高,为186.16 g/L。综合考虑,优化得到3.7 mmol/L为水培生菜适宜的营养液钾浓度。

Taking "Flanders" lettuce as research object,five nutrient solution potassium concentrations of 0. 6( T1),1. 5( T2),2. 4( T3),3. 0( T4) and 6. 0( T5) mmol/L-1 were set up to explore effects of different nutrient solution potassium concentrations on growth,yield,quality,nutrient solution consumption and nutrient solution utilization efficiency of hydroponic lettuce. Results showed that,T4 treatment had the largest leaf area,which increased by 9. 33% - 65. 91% compared with other treatments. Potassium concentration treatment of nutrient solution had no significant effect on SPAD value of lettuce leaves.T4 treatment had the largest crown fresh weight,which increased by 5. 91% - 145. 82%,the root fresh weight of T3 treatment was the largest,which increased by 0. 30% - 71. 88% compared with other treatments. Potassium concentration of nutrient solution was negatively correlated with soluble sugar of lettuce,and it had no significant effect on VC content and no significant effect on lettuce nitrate content. T1 treatment consumed the least nutrient solution,which was 16. 01% - 35. 63% less than other treatments. T5 treatment consumed the most nutrient solution,which was 2. 39% - 55. 48% more than other treatments. T1 treatment has the lowest nutrient solution utilization efficiency,nutrient solution utilization efficiency of T4 treatment was the highest,which was 2. 21% - 61. 89% higher than other treatments. Through relationship between lettuce yield,nutrient solution utilization efficiency and nutrient solution potassium concentration,optimization of nutrient solution potassium concentration was established. When nutrient solution potassium concentration was 3. 9 mmol/L,yield of lettuce was the highest,which was142. 03 g/plant;when potassium concentration of nutrient solution was 3. 5 mmol/L,nutrient solution utilization efficiency of lettuce was the highest,which was 186. 16 g/L. Based on comprehensive considerations,3. 7 mmol/L was optimized to be optimum potassium concentration in nutrient solution for hydroponic lettuce.