トマトの水耕栽培における肥培管理と養分吸収 : Logistic式による数値解析

Tomatoes were cultivated by hydroponics, in which a nutrient solution was managed on the basis of only two indexes(pH and Ec) and the composition of additional fertilizer was always kept constant. This simplification in nutrient management caused virtually no decrease in the yield of tomato fruits, though the concentrations of a few nutrients varied greatly during cultivation from their initial concentrations. Thus, it was judged that this simplified method of management is applicable to practical hydroponic culture. It was also confirmed that the cumulative amounts of nutrients, such as N, P, K, Ca, and Mg, absorbed by a tomato plant during cultivation fit well to the Logistic equation in which cumulative temperature is used as an independent variable.