Acid sulfate soils are usually found in lowland areas with generally flat topography around beaches or large rivers and are influenced be sea or river tides, so that within a certain period of time experience flooding. Acidic conditions and often flooding often cause acid sulfate soils to have low fertility levels. Such conditions can be improved by adding organic materials like chicken manure and rice husk bio char. The research method used was factorial in a Completely Randomized Design (CRD) the first factor was rice husk bio char which consisted of three levels of 0, 5, and 10 t ha^-1.  The second factor was chicken manure 0, 10, and 15 t ha^-1. Each treatment has three replications so there were 27 experimental units. Chicken manure and rice husk bio char, increased soil pH and reduced the potential for Fe, exchangeable-Al, and redox potential. The treatment of 5 t ha^-1 rice husk bio char + 10 t ha^-1 chicken manure was able to increase soil pH, reduce redox potential, exchangeable-Al and dissolved Fe to the greatest effect.