Improving Post-Nickel Mining Soil Quality Using Biochar, Humic Acid, and Mulch Derived from Oil Palm Empty Fruit Bunches

The physics and chemistry properties of post-mining soil needs to be improved. It isnot suitable for agriculture, so alternative technology is required such us using biochar madefrom oil palm empty fruit bunch and mycorrhiza. This study aims to examine the effect of biocharmade from oil palm empty fruit bunch and mycorrhiza to improve the nickel post-mining soilquality. This study randomized group design with 4 levels; B0 (0 t/ha), B1 (10 t/ha), B2 (20 t/ha),and B3 (30 t/ha) with 4 levels; M0 (0 t/ha), M1 (0.8 t/ha), M2 (1.6 t/ha), each treatment wasrepeated 3 treatments so that the total experiment was 36 units. The results showed that the useof bio-ameliorant waste from oil palm empty fruit bunch with dosage of 30 t/ha, significantlyimproved the chemical properties of nickel post-mining soil regarding the parameter of C-organic, pH, available phosphorus, cation exchange capacity, exchangeable aluminium, Ca-ddand Mg-dd. The treatment of mycorrhiza 4 g significantly affected the soil properties regardingimprovement of soil chemical properties in available phosphorus to plants and exchangeablealuminium parameters. The treatment of biochar with dosage of 30t/ha of soil and mycorrhiza1.6 t/ha (B3M2) of soil is the bestinteraction of mycorrhiza and biochar made from oil palmempty fruit bunch as amelioration material of post-mining soil which is characterized by thedecrease of exchangeable aluminium. The application of biochar made from oil palm empty fruitbunch and mycorrhiza can improve the nickel post-mining soil quality.