**6. Conclusion**

Rice fields in Indonesia are used very intensively, and the fertility is negatively affected following the decrease in pH. Furthermore, the paddy fields in Indonesia have experienced heavy metal pollution, especially Pb and Cd, which is indicated by their accumulation in soil and rice. These heavy metals come from phosphate fertilizers and industrial waste. The proposed solution uses organic materials to immobilize the metal or form ligand bonds. Cadmium and lead input from phosphate fertilizers threaten the environment and human health due to soil contamination, crop absorption, and bioaccumulation in the food chain. A decrease in non-polluted recycled and mineral P fertilizer dependence could alleviate the Cd and Pb pollution of the paddy soils.
