The porous structure of biochar promotes ability to absorb soluble organic matter, gases, and inorganic nutrients. These characters are indeed highly suitable habitat for microbes to colonize, grow, and reproduce. A series of research was carried out aiming at to study the possibility of using biochar from palm kernel shell as bio-ameliorant carrier material for aggregate stabilizing microbes and determine the effectiveness of the newly-constructed bio-ameliorant in an Ultisol. Biochar was examined their physicochemical characteristics and the microbes population residing in it over time. Fourier-transformed infrared spectroscopy (FTIR) was used for obtaining vibrational spectra of the biochar that related to promote organo-mineral complexes of functional groups. The results indicate that biochar was suitable carrier material as it has highest total pore spaces and available water content in the newly-constructed bio-ameliorant compared to peat and compost. Microbial population obtained from the granular forms of bio-ameliorant was 107 cfu/g of the sample until 12 months shelve-life periods. Biochar showed intensive bands in the range of 3413-3400/cm corresponding to the stretching band of O-H (hydroxyl) and N-H amine). In the region 1170-950 /cm, bio-char exhibited the absorption characteristic at 1034/ cm corresponding to the existence of O-CH3 vibrations. The best vegetative growth performance of Bisma variety in Ultisol at Experiment Station Taman Bogo, Lampung, was shown by the application of 100% standard dosage of NPK conventional fertilizers in combination with the addition of 4.2 g bio-ameliorant/tree. Yield of dry grain of maize was higher (+15.7%) by application of 100% standard dosage and 2.1 g bio-ameliorant/tree (112 kg/ha) than that obtained by standard dosage of conventional fertilizer