Abstract
The objective of this study was to establish a cultivation method for leafy vegetables and tomatoes with low potassium content for dialysis patients who are restricted potassium intake, while still maintaining normal plant growth. Three types of leafy vegetables were grown hydroponically with no potassium application during the latter half of their growth period. Tomatoes were grown hydroponically under two different conditions 1) in a nutrient solution without potassium, and 2) in a nutrient solution alternated every week with and without potassium. The potassium content of leafy vegetables in the potassium restricted group was 30–40% of the control, with no change in plant growth. The potassium content of the tomatoes in the potassium restricted group was also reduced to 50–89% of the control. There was no change in the fresh weight per fruit of the tomatoes; however, the total yield was reduced. In addition, reduction in the potassium content was accompanied by an increase in the sodium and magnesium content of the leafy vegetables and tomatoes. The increases in sodium and magnesium content occurred to compensate for the decline in potassium content so that the growth of the plant was not inhibited.
