Indonesia has vast saline land that remains underutilized due to low productivity, making it unsuitable for agriculture. Efforts to mitigate salinity’s negative impact on plant growth and yield have focused on organic soil amendments to enhance fertility and productivity. This study evaluates the effects of organic manure and biochar on saline soil properties and identifies the optimal biochar-to-manure ratio over a 91-day incubation. The experiment was conducted using a Completely Randomized Design (CRD) with nine treatments, each replicated three times. The treatments included soil-only (SO), chicken manure (CM), three ratios of chicken manure and biochar (1:1, 1:2, and 1:3), goat manure (GM), and three ratios of goat manure and biochar (1:1, 1:2, and 1:3). Key parameters measured were soil organic carbon, pH, electrical conductivity (EC), available phosphorus (P), total nitrogen (N), cation exchange capacity (CEC), and exchangeable cations. The findings show that the addition of biochar, particularly at higher ratios, significantly enhanced soil organic carbon, CEC, available P, and total N while stabilizing soil pH and reducing EC and exchangeable sodium percentage (ESP). The combination of chicken manure and biochar at a 1:3 ratio yielded the most substantial improvements across most parameters. These results underscore the potential of tailored combinations of organic manure and biochar to optimize soil fertility and support sustainable agricultural practices.