ABSTRACT Bird’s eye chili (Capsicum frutescens L.) is an important horticultural commodity in Indonesia; however, its production in Riau Province decreased from 7.4 tons in 2022 to 6.6 tons in 2023 due to unfavorable soil conditions, particularly high soil acidity. Efforts to improve soil conditions were carried out using oil palm empty fruit bunch (EFB) ash as an ameliorant, along with NPK …