Utilization of liquid waste from freshwater fish cultivation in bioreactors batch culture system and biochar to increase lettuce plant production (Lactuca sativa L.)

Abstract

The utilization of freshwater fish cultivation and agricultural wastes can be an alternative in increasing vegetable production. Freshwater fish waste can be used as liquid organic fertilizer, while agricultural waste in the form of rice husk can be used as biochar which has the potential to improve soil fertility.The The purpose of this study was to evaluate the treatment of watering freshwater fish waste as a liquid organic fertilizer that affects the production of lettuce plants, as well as to evaluate the rice husk biochar treatment that can affect the production of lettuce plants. This study used a factorial randomized block design with 3 replications. The factors used in this studied were Factor I: watering frequency of freshwater aquaculture wastewater, consisting of without watering wastewater (L0); watering twice a week (L1); and watering 4 times a week (L2); and Factor II: dosage of rice husk biochar, consisting of without rice husk biochar (B0); 10 g of rice husk biochar per polybag (B1); 20 g of rice husk biochar per polybag (B2). The result showed that:(1) liquid waste from freshwater fish cultivation in bioreactor batch culture system can be used as liquid organic fertilizer in lettuce cultivation, and (2) watering frequency of liquid organic fertilizer from freshwater aquaculture wastewater 4 times a week and rice husk biochar 20 g per polybag were the best treatment for lettuce yield.