Effect of biochar type on planting media with different heavy metal containments of Pb, Cd, And Cr on growth, results and quality of padi results (Oryza Sativa L.)

Heavy metal pollution in agricultural soils has become a serious issue, especially in paddy fields located in the downstream of Tukad Badung River, Bali. This study aimed to analyze the effect of biochar types on growing media with heavy metal content of Pb, Cd, and Cr on growth, yield, and quality of rice (Oryza sativa L.). The planting medium was taken from heavy metal polluted soil in the region. The biochar used came from rice straw and husk, coconut husk and shell, and fruit and vegetable waste. The research was conducted using a one-factor randomized group design (RAK) with 27 treatment combinations (3 types of heavy metals × 3 types of biochar × 3 replications). The results showed that coir and coconut shell biochar gave the best effect in reducing heavy metal mobility in soil and increasing rice yield, with a 40% reduction in grain heavy metal content. In conclusion, biochar is an effective and environmentally friendly solution to mitigate heavy metal contaminated soil and increase agricultural productivity.