Formulation of biochar-compost and phosphate solubilizing Fungi from Oil palm empty fruit bunch to improve growth of maize in an Ultisol of Central Kalimantan

The efficiency of phosphorus uptake by plants in an Ultisol soil is very low because most of the soil phosphorus is precipitated by Al and Fe. Oil palm empty fruit bunches can be used as basic materials of biochar and compost, and as sources of isolates of phosphate solubilizing fungi. This study was aimed at elucidating the effect of application of phosphate-solubilizing fungi with biochar and the compost produced from oil palm empty fruit bunches on the growth and yield of maize an Ultisol of Central Kalimantan. This study consisted of two experiments. The first experiment was inoculation of four isolates of phosphate solubilizing fungi isolated from of oil palm empty fruit bunches, i.e. Acremonium (TB1), Aspergillus (TM7), Hymenella (TM1) and Neosartorya (TM8) to 'biocom' media (mixture of biochar and compost generated from oil palm empty fruit bunches) to obtain phosphate-solubilizing fungi that can adapt to the media. In the second experiment, the best results in the first experiment were applied to an Ultisol soil planted with maize. The results showed that the isolates that were best adapted to biocom media were Aspergillus-TB7 with 60:40 proportion (60% biochar + 40% compost) and Neosartorya-TM8 with 70:30 proportions (60% biochar + 40% compost). The use of the first experiment results in the second experiment showed that the application of biocom plus Neosartorya-TM8 (BTM) on an Ultisol soil significantly improved the growth and yield of maize, as well as its the phosphorus uptake and uptake efficiency.