Exploring the Potential of Struvite as a Partial Fertilization Component for Endive (Cichorium endivia L.) in Soilless Cultivation

Abstract Soilless cultivation facilitates efficient and intensive crop production, without the need for soil, making it an effective method for urban agriculture applications. However, soilless cultivation systems predominantly rely on the use of synthetic fertilizers. Therefore, the current study was conducted to evaluate struvite, produced from the digestated effluents of anaerobically treated livestock waste, as a complete replacement to phosphorus fertilizers, for the soilless cultivation of endive ( Cichorium endivia L.). Three rates of struvite (St1 as base level, St2 and St5) were used to evaluate the dissolution and availability of struvite. Additionally, conventional and struvite fertigation solutions were applied to examine different methods of delivery. The effects on agronomic and physiological parameters, antioxidant capacity, nutrient accumulation and produce quality and storage were assessed. Struvite produced similar yields to the application of triple-superphosphate, while increased struvite rates stimulated plant growth. The base struvite rate elicited similar responses on the antioxidant activity of plants. However, it was associated with increased oxidative stress, alleviated by the increased struvite rates. In terms of yield, quality and post-harvest attributes, the base struvite rate exhibited comparative performance to conventional fertilizers, whereas the highest struvite rate produced comparable results to the conventional treatment supported by additional fertigation, demonstrating a high efficacy as a slow-release fertilizer. These findings emphasize the potential of struvite as an effective fertilizer alternative. However, further research is necessary to optimize struvite application, considering the material’s characteristics, the cultivation methods and plant species. Graphical Abstract