Resumo

VELEZ-CARVAJAL, Nohora Astrid; MELO-MARTINEZ, Sandra Esperanza  e  FLOREZ-RONCANCIO, Víctor Julio. Behavior of Ca, Mg and S in a soilless culture system for carnation. Rev. Chapingo Ser.Hortic [online]. 2014, vol.20, n.2, pp.171-185. ISSN 2007-4034.  https://doi.org/10.5154/r.rchsh.2013.10.038.

In the hydroponic growing systems of the Bogota plateau, excess amounts of ions have been found in the leachate. The aim of the study was to determine the Ca, Mg and S contents in the substrate, leachate and tissue of the entire plant of the standard carnation cv. Delphi, with three leachate recirculation percentages and in different phenological development stages. A randomized complete block experimental design in split plots with nine treatments and three replications was used. The calcium concentration in the leachate on the basis of recirculation was significantly higher without recirculating the leachate, whereas, on the basis of the substrates, it tended to be higher in the substrate with a lower percentage of burned rice husk (BRH). For magnesium, the concentration in the leachate increased with crop development, regardless of the factors, and was significantly greater as the recirculation percentage increased. The calcium and magnesium contents were significantly lower in the substrate with higher BRH content. The sulfate concentration in the leachate increased as the recirculation percentage increased, and the highest concentrations occurred under the influence of the substrate with higher coconut fiber (CF) content. In closed systems the magnesium and sulfur concentrations in the fertigation formulas must be adjusted. Furthermore, when CF percentages are maintained in the substrate, it is necessary to consider the retention of the calcium and magnesium ions.

Palavras-chave : Secondary macroelements; organic substrates; cut flower.