Plant growth and fruit harvest were assessed
weekly according to the criteria established in productive horticulture [22]. The produced biomass
was harvested at least at the end of the experiment,
and wet weight, dry weight and in some occasions
elemental composition of biomass (Carbon, Nitrogen, Phosphorus) were determined. Analyses on
tomato biomass were done by Labor fuer Boden
und Umweltanalytik in Zurich using Kjehldahl,
photometry, Atomic Absorption Spectroscopy
(AAS) or Inductively coupled plasma (ICP). For
cucumbers and aubergines, values for dry matter
and Nitrogen, Phosphorus and Potassium (NPK)
content were used from literature [24,25].