Alternative Phosphorus Fertilisation with Bio-Based Pellet Fertilisers: A Case of Study on Ryegrass (Lollium perenne L.)

The European Union (EU) advocates for a sustainable agricultural model with reduced synthetic fertiliser use. This study compares different high-P organo-mineral pellet fertilisers (OMFs) and their effects on crop yield. A trial was conducted under controlled conditions in ryegrass (Lollium perenne L.) pots with different organo-mineral fertilisation strategies at sowing with adjusted doses of P (120 kg P ha−1) and N (200 kg N ha−1). Pellets were developed from compost enriched with bone meal (OMF-BON), struvite (OMF-STR), and monoammonium phosphate (OMF-MAP). Conventional fertilisers (Complex15 and MAP) and alternative unpelletised/pelletised sources (STR and BON) were also tested. The experimental design included an unfertilised control (C), and treatments were carried out in triplicate (N = 24). Over 40 days, three cuttings (10, 25, and 40 days) were collected to determine fresh/dry biomass, nutrient content, and N, P, and K extraction efficiency. Soil labile parameters were influenced by the application of fertilisers especially OMF-MAP, OMF-STR, and MAP. MAP and STR yielded the highest nutrient extraction and biomass production, followed by their pelletised forms (OMF-MAP and OMF-STR). These results highlight the potential of pelletised organo-mineral fertilisers as sustainable alternatives to conventional sources.