Biochar‑compost mixture as amendment for improvement of polybag‑growing media and oil palm seedlings at main nursery stage

Purpose Production of oil palm seedling in the nursery mainly utilises top soil as polybag medium. These soils, especially in tropical regions, are acidic and have low organic matter content. The aim of this study was to investigate the efects of oil palm empty fruit bunch (EFB) biochar and compost incorporation as amendment in polybag medium for oil palm seedlings growth at the nursery stage. Methods A polybag experiment was conducted with four biochar rates (۰, ۰.۵, ۱.۰ and ۱.۵% w/w C addition), two compost rates (۰ and ۳۰% v/v), and two fertiliser application rates (۷۵ and ۱۰۰% of recommended rate). The efects of biochar, compost, and biochar-compost combination on oil palm seedling growth was evaluated and the efectiveness of EFB biochar in retaining soil nutrients was determined indirectly by measuring amount of nutrient leached through the polybag medium. Results Biochar, compost, and biochar-compost amendment improved polybag media’s chemical properties (pH, total C and N, C:N ratio, CEC, Mg, and Ca). There were no signifcant efects of the amendments on shoot biomass. However, root growth and shoot:root ratio signifcantly improved with ۱.۵% w/w C addition and ۳۰% (v/v) compost with ۷۵% recommended fertiliser rates applied. Furthermore, nutrient leaching measurement indicates that, EFB biochar signifcantly reduced ammonium-N leaching up to ۲۱–۴۶%. Conclusions Overall, this study demonstrates the potential of biochar and compost co-application to improve the chemical properties of polybag medium and root development of oil palm seedlings.

کلیدواژه ها:

Oil palm nursery  ، Oil palm waste  ، Biochar  ، Compost  ، nutrient retention