葉萵苣行浮根式水耕,以不同濃度之Hoagland培養液測定結果,該培養液二分之一濃度生產量最高。經培養液和植體之分析計算其大致培養液吸收濃度NO3-N、P、K•Ca、Mg分別爲7、15、4.5、2.5、1me/l。浮根式水耕其主要氧來源爲水表面供給爲主,用馬達以循環法入方法,雖可略增加其溶氧量,但對葉萵苣之產量影響不顯著。
By using root-floating hydroponics, different concentrations of Hoagland solution were tested for nutrient absorption of leafy lettuce. Highest yield was obtained 1/2 concentration of standard solution. Results from the analysis of nutrient solution and plant suggested the optimum nutrient absorption for leafy lettuce being NO3-N=7, P=1.5, K=4.5, Ca=2.5, Mg=1 me/l. Needed oxygen mainly came from the surface of water in root-floating hydroponics. Water circulating did not increase the lettuce yield.