The role of soil ameliorants and arbuscular mycorrhizal fungi in improving the growth of <i>Samanea saman</i> (Jacq.) Merr seedlings in coal mine post-mining media

Improvement of coal post-mining soils is necessary to increase the success of reclamation activities. Organic and inorganic materials are often used as soil improvers (ameliorants), and are usually combined with microorganisms, one of which is arbuscular mycorrhiza fungi (AMF), to support and improve the success of revegetation activities on post-mining land. This study aims to evaluate the application of soil ameliorants and AMF in increasing the success of revegetation in coal post-mining media. The study used a completely randomized design (CRD) with a split plot design consisting of three treatments, namely: AMF, soil ameliorants (compost, lime and FABA (fly ash and bottom ash)) and exposure to Al and Fe, and the plants used were Samanea saman. The results showed that AMF treatment combined with compost and lime ameliorants, as well as exposure to Al and Fe were able to increase the growth of S. saman seedlings. In addition, the combination of AMF and ameliorants was also able to increase the chlorophyll content of SPAD. All AMF treatments were able to produce high root colonization (60-100%). The AMF treatment was also able to increase the uptake of N and P nutrients. The provision of FABA ameliorants was able to increase soil pH from slightly acidic to slightly alkaline, and caused the unavailability of P-available elements. S. saman is very suitable for planting in revegetation of post-mining land, with compost and FABA ameliorants. FABA has the potential to be used as a substitute for lime.