Root-zone Heating in Winter Using N.RECS is Effective for Promoting Growth and Flowering of Pot Flowers and Reducing Energy Consumption for Heating

Abstract

Winter heating energy saving is an important issue, not only for reducing production costs, but also for reducing CO₂ emissions during cultivation. This study investigated the effect of root-zone heating using a new root-zone environmental control system (N.RECS) in winter on the growth and flowering of pot flowers and the reduction in heating costs. Bulbous begonia, geraniums, dwarf gerberas, and New Guinea impatiens, which require relatively high temperatures, were used in the present study. This experiment consisted of two plots: a conventional plot (control) with a minimum air temperature of 16°C and no root-zone heating, and a root-zone (RZ) heating plot with a minimum air temperature of 12°C and root-zone heating of 24°C. The results showed that RZ heating significantly promoted the growth and flowering of all tested pot flowers. Heating costs for bulbous begonia, geranium, and dwarf gerbera were reduced by 28–45% in the RZ heating plot compared to that of the control. In New Guinea impatiens, heating costs were not reduced by RZ heating because this experiment started late, in mid-March, and heating costs in the control were low. CO₂ emissions were roughly proportional to energy costs. In conclusion, root-zone heating with the N.RECS enabled the early production of high-quality plants in winter cultivation of pot flowers with relatively high temperature requirements and could contribute significantly to the reduction of CO₂ emissions during the cultivation period by reducing heating costs.