不同DFT装置对生菜产量和品质的影响

为经济解决DFT栽培中根际溶氧问题，试验设计了4种结构特点不同的DFT装置，以意大利耐抽苔生菜为试验对象，研究不同DFT装置对生菜产量和品质的影响。结果表明，循环浮板法(CFS)栽培能够稳定供给植株生长所需要的养分和氧气，生菜产量最高，品质较好；支撑浮板法(SFS)栽培虽然不能使营养液中的溶氧达到理想水平，但暴露在空气中的根系可以吸收空气中的氧气，植株生长良好，维生素C含量最高，硝酸盐含量最低，与其他3种处理的差异达极显著水平；浮板法(FS)和动态液位法(DSS)中生菜产量相对较低，要想合理地应用这两种栽培方式，还需要对其结构和系统设计中的某些参数进行修改和设定。综合生菜产量因子与商品性状，支撑浮板法是最适宜的DFT方式。

Effect of different deep flowing technique installations on yield and quality of lettuce

To solve the problem of the dissolved oxygen in deep flowing technique(DFT), the authors designed four different installations. And to study the effects of the four different DFT installations on yield, quality of lettuce, the authors performed experiments on Italian very late bolt lettuce. The results show that the installation of circulating floating system(CFS) can supply plant with needed nutrient and oxygen, every index of yield reaches the highest level and the quality indexes reach perfect level; The installation of supported floating system(CFS) cannot ensure a large amount of oxygen dissolve in nutrient solution but because of the roots exposing the atmosphere can absorb the oxygen in the air, the plants develop well. The content of vitamin C is the highest and the Nitrate is the lowest which has extremely remarkable difference from the plants in the other three treatments. Meanwhile, floating system and dynamic solution surface restrain the growth of plants in some aspects. If people want to use these two systems they need to modify some parameters of their structures and circulating system. From the results of this experiment, SFS is the best DFT system in Beijing.