The optimization of rice production in tidal swamplands through bio-organic fertilizers and improved cropping systems addresses critical food security challenges in Indonesia amid growing population pressure and diminishing agricultural lands. These acid sulfate tidal swamplands in South Sumatra represent substantial yet underutilized potential due to extreme soil acidity (pH 3.0-4.0), while conventional chemical fertilizer-dependent cultivation causes environmental degradation and increases production costs. This research urgently explores sustainable approaches that utilize local organic resources while reducing chemical inputs, potentially transforming marginal lands into productive agricultural areas that contribute to national food security and improve coastal farmers' livelihoods. This research investigated the combined effects of bio-organic fertilizer and modified planting systems on rice production in acid sulfate tidal swamplands of South Sumatra, Indonesia. The study employed a factorial Randomized Block Design with four fertilizer treatments (control/no fertilizer, NPK fertilizer, bio-organic fertilizer, and bio-organic fertilizer with 50% NPK) and three planting systems Tabela or Direct Planting System (DPS), Jajar Tehel or Square Planting System (SPS), and Jajar Legowo or Legowo Row Planting System (LRPS). Bio-organic fertilizer was produced from rice straw and poultry manure (60:40 ratio) enriched with Azospirillum and phosphate solubilizing bacteria. Research was conducted on strongly acidic soil (pH 3.0-4.0) using Ciherang rice variety. Data collection included soil parameters, plant growth metrics, and yield components. Results demonstrated that the integration of bio-organic fertilizer with reduced NPK (50%) under the Jajar Legowo planting system significantly enhanced rice productivity, achieving the highest yield of 6.70 t/ha, representing a 252.63% increase compared to the control. This integrated approach also improved chlorophyll content (42-46 SPAD units), with Jajar Legowo showing the most pronounced response to bio-organic amendments (7-9 SPAD unit increase). Macronutrient uptake analysis revealed differential absorption patterns (K > N > P) with strong positive correlations to treatment combinations. The study concludes that integrating bio-organic fertilizers with reduced chemical inputs and optimized planting geometry effectively addresses the challenges of tidal swampland cultivation, offering a sustainable approach to rice production in marginal lands while maintaining high productivity and reducing environmental impact.