Effects of amount of irrigation and ionic concentration of nutrient solution on the growth and absorption of ions and water by Dianthus caryophyllus in a closed system.

摘要

Effects of amount of irrigation and ionic concentration of nutrient solution on the growth and nutrient absorption of ions and water by D. caryophyllus 'Desio' were investigated. The optimum ionic strength was 2.0 dS.m-1 (2S) with the amount of irrigation of 100, 150, and 200 mL/day/plant (2V) at each growth stage. At higher ionic strength (3S), the nutrient solution became rapidly acidic and the EC was unstable. Moreover, the uptake of some ions, such as K, was unstable. On the contrary, at low ionic strength levels (1S) the uptake of bivalent ions was depressed. The amount of irrigation had no significant effect on plant growth and nutrient uptake. There was no significant difference between a closed and an open system in plant growth and flowering. The recommended change in n/w values for the composition of a new nutrient solution were NO3- 9~12 -> 10~14 -> 13~15, Ca 10~11 -> 9~10 -> 7~9, and Mg 2~3 -> 1~2 -> 0~1 me.L-1 with progress of growth, while NH4+, P, and K values were fixed at 2-3, 0-1, and 2-3 me.L-1, respectively, for the entire growing period. This solution showed higher values for P and K, and lower values for NO3- and Ca as compared with other solutions.