Acidic soils are marginal soils with low pH, dominated by Al and Fe ions which can bind essential nutrients such as P. Dissolving P and K from sources in the soil can be accelerated by microbial activity and ameliorant materials, also to improve nutrient availability and other soil properties. This study aimed to determine the effect of inoculation growth promoting bacteria and ameliorants to improve the chemical properties of acid soils and rice nutrient uptake of P and K. The research was conducted in greenhouse of Agriculture Faculty, Universitas Jember, from November 2021 – April 2022. It used a completely randomized design with two factors and three replications: ameliorant materials namely organic matter (A1), gypsum (A2), dolomite (A3), and NPK fertilizer (A4). The second factor was the inoculation of growth-promoting bacteria, namely without inoculation of bacteria (P0), phosphate solubilizing bacteria (PSB) (P1), potassium solubilizing bacteria (KSB) (P2), and a combination of PSB and KSB (P3). The bacterial species used were Bacillus valezensis and Bacillus sp.. The rice variety used was the local Pendok rice variety. The results showed no interaction between the application of growth-promoting bacteria and ameliorant. Ameliorant factor affected the increase in soil pH, the P concentration, and the uptake on the shoot of rice plants. The treatment of organic matter ameliorant and gypsum increased the phosphorus content of the plant canopy tissue by 0.420% to 0.426%. The P uptake of the rice plant shoot was increased by up to 27.59% with the addition of gypsum compared to the addition of NPK fertilizer. ABSTRAK Tanah masam merupakan tanah marjinal dengan pH yang rendah, didominasi ion Al dan Fe yang dapat mengikat unsur hara esensial seperti P. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian bakteri pemacu tumbuh dan amelioran terhadap perbaikan sifat kimia tanah masam dan serapan hara P dan K tanaman padi. Pelaksanaan penelitian di rumah kaca Fakultas Pertanian Universitas Jember pada November 2021 – April 2022 menggunakan Rancangan Acak Lengkap 2 faktor dan diulang tiga kali, faktor pertama Amelioran (A): bahan organik (A1), gypsum (A2), dolomit (A3), dan pupuk NPK (A4). Faktor kedua yaitu : (1) tanpa inokulasi bakteri (P0), (2) bakteri pelarut fosfat (BPF) (P1), (3) bakteri pelarut kalium (BPK) (P2), dan (4) kombinasi BPF dan BPK (P3). Spesies bakteri yang digunakan adalah Bacillus valezensis dan Bacillus sp.. Varietas padi yang digunakan adalah varietas padi lokal Pendok. Hasil penelitian menunjukkan tidak terdapat interaksi antara aplikasi bakteri pemacu tumbuh dan amelioran. Amelioran berpengaruh terhadap pH tanah, serta peningkatan kadar dan serapan hara fosfor pada jaringan tajuk tanaman padi. Perlakuan amelioran bahan organik dan gypsum meningkatkan kadar fosfor jaringan tanaman bagian tajuk sebesar 0,420% hingga 0,426%. Serapan hara P bagian tajuk meningkat hingga 27,59% pada penambahan amelioran gypsum dibanding penambahan pupuk NPK. Aplikasi bahan amelioran memberikan perubahan yang lebih nyata dibanding perlakuan inokulasi bakteri pemacu tumbuh.