Investigation of biomass ash vermicompost as nutrient rich growing media for impatiens

Agro-industry and bioenergy plants produce a huge amount of biomass ash (BA) and bio-waste. Recycling this waste in the ornamental industry is beneficial for the environment and produces nutrient-rich growing media. Hence, present study was conducted at two consecutive stage aiming to evaluate the vermicomposting of BA with cattle manure and its use as a growing media component with hazelnut husk (HH) to enhance flowering performance of Impatiens walleriana. Five treatments T₀ (commercial coco peat), T₁ (vermicompost:HH), T₂ (BA-vermicompost equal to 3.5% NPK:HH), T₃ (BA-vermicompost equal to 7.0% NPK:HH), T₄ (BA-vermicompost equal to 10.0% NPK:HH) were evaluated. The results indicated that BA significantly increased nutrient content of vermicompost, likewise pH. Accordingly, nutrient bioavailability decreased as pH increased. The bioavailable fraction of nutrients was in the range of 4.45 ± 0.12% (P) to 46.26 ± 1.52% (K). Similar plant growth parameters were observed with BA-vermicompost at 7.0% NPK (T₃) and commercial control media compared with low or higher BA-vermicompost-containing media. Likewise, chlorophyll contents were significantly higher in control and T₃ treatments; only plants on T₄ indicated chlorosis symptoms caused by pH and nutrient imbalance. The combined BA-vermicompost and HH improved the inflorescence trend, similar to the control. Therefore, recycling these wastes as nutrient-rich growing media for bedding flowers is appropriate for horticultural sustainability.