Reuse of cucumber drainage nutrient solution in secondary crops in greenhouses: Initial results

Abstract

In the current study, a cascade hydroponic cultivation model was tested where the drainage nutrient solution of a primary crop (cucumber) was reused for the fertigation of different secondary crops with higher resistance on salinity. For this purpose, different herbs, namely rosemary (Rosmarinus officinalis), basil (Ocimum basilicum) and mint (Mentha × piperita) were grown in perlite slabs in order to evaluate their response on irrigation with drainage solution from a perlite cucumber crop. Three different irrigation treatments were imposed: i) standard nutrient solution, ii) drainage solution mixed with standard nutrient solution, and iii) drainage solution diluted with water. Measurements of nutrient solution volume input and output were carried out along with crop growth parameters. It was found that basil presented the highest growth rate when irrigated with diluted drainage solution. Rosemary and mint, on the other hand presented the best performance when irrigated with a standard nutrient solution. It was also found that the use of the cascade hydroponic system improved the crop water use efficiency in the greenhouse. The work is carried out in the frame of the CasH project that is co-financed by the European Union and Greek national funds through the bilateral Greece-Germany S&T Cooperation Program, Competitiveness, Entrepreneurship & Innovation (EPANEK) (project code: T2DGE-0893). © 2020 International Society for Horticultural Science. All rights reserved.