Nutrient solution management recirculating soilless culture of rose in mild winter climates

Abstract

In a closed hydroponic system with a rose crop, the composition of the nutrient solution in the tank was measured every two days in order to establish the dynamics of the nutrient elements in short-term periods. It was observed that the concentration of Fe decreased very fast and that the concentrations of Ca2+, Mg2+ and Cl- increased. The concentrations of K+, Ca2+ and SO4 2- did not reach critical levels. The Cl- content of commercial fertilizers was measured and it was concluded that the addition of some fertilizers (e.g, Fe-EDDHA) would lead to an accumulation of Cl- in the nutrient solution. Thus, Cl- free fertilizers should be used. The analysis of the Fe, NH4 and PO4 balance in the nutrient solution seems to be required to determine the necessary corrections to increase the life span of the nutrient solution.