The plant factory to control growing system automatically is necessary to cultivate single-node cutting rose, which produce large numbers of uniform shoots per unit area in short cultivation. However, the recirculation of the nutrient solution in closed system leads to several problems. One of them is connected with the quality of nutrient solution and the supply of minerals. The uptake of specific nutrients depends on growth and development, or plant stage, which results in a shift in ionic ratio in the drainage water compared to the nutrient solution supplied. Consequently, the nutrient supply should be controlled to be equal to the demand of the plant to avoid disorder of nutrient solution, such as depletion or accumulation. Therefore this study was conducted to examine the effect of mineral nutritional control on nutrient uptake of single-node cutting rose `Red velvet' and `Vital' in a plant factory. The nutritional control of nutrient solution was conducted by five methods: the control of electrical conductivity (EC), N, P, and K elements (NPK), macro elements (M), macro and micro elements (MM) to target ranges in root zone, and the supplement of nutrient solution (S). In NPK, M, and MM control system, the input of nutrients was calculated as amounts of absorption by the plants compared to target values in root environment. The fertilizer supplement of N, P, and K was lower in EC control system than other control systems. In EC and S control system, the concentration of NO3- -N and K in root zone exceed optimal range whereas P, Ca, and Mg decreased at the later stage of growth. The concentrations of each nutrient in root environment were kept at the target ranges in M and MM control system, which showed optimum yield and product quality.
Nutrient uptake and assimilation under varying day and night root zone temperatures in lowland rice
