Effect of Biochar Type on Planting Media Contaminated with Heavy Metals Pb, Cd, and Cu on Growth and Yield of Rice (Oryza sativa L.) as well as Bioaccumulation Factor and Translocation Factor

Most people around the world, especially Indonesia, use rice (Oryza sativa L.) as a staple food. Rice plants from agricultural land downstream of the Badung River are suspected to have indications of heavy metal contamination due to pollution of the Badung River which is used as irrigation in Subak Kerdung agricultural land. This study aims to evaluate the effect of various types of biochar on planting media polluted with heavy metals on growth, yield, Bioaccumulation Factor (BAF), and Translocation Factor (TF) in rice plants. This study used a 3-level Randomized Group Design (RAK) of biochar types (rice straw and husk, fruit and vegetable waste, and lignohumic from wood waste) with 9 replications. The results showed that rice plants obtained from Subak Kerdung agricultural land showed that rice plants detected heavy metal content of Pb, Cd and Cu exceeded the maximum limit of heavy metals allowed in plants according to WHO (World Health Organization). Biochar is able to significantly reduce heavy metal levels in the growing media. Lignohumic-based biochar proved to give better results in increasing rice yield. Cu metal consistently had the highest accumulation ability (BAF) and translocation (TF) across biochar treatments and tended to be more easily absorbed and translocated by plants. In contrast, Pb metal showed the lowest bioaccumulation and translocation values, indicating that it is relatively difficult to be accumulated by plants, and its distribution from roots to shoots is very limited.