摘要：Soil biomass carbon microorganism (C-mic) is one indicator of soil fertility. The application of humic acid, vermicompost aqueous extract, and P fertilization applied to the soil will affect the activity of soil microorganisms. This research aimed to study the effect of application of humic acid, vermicompost extract, and P fertilization on C-mic. The first factor was the application of humic acid (H), namely without the application of humic acid, the application of humic acid of commercial origin, and application of humic acid-like from watery extract vermicompost. The second factor is P (P) fertilization which is divided into 4 dose levels, namely without TSP fertilizer, TSP fertilizer 100 kg ha-1, TSP fertilizer 200 kg ha-1, and TSP fertilizer 300 kg ha-The data obtained were tested for homogeneity of variance with the Bartlett test and the additiveity of the data was tested with the Tukey test. The data were analyzed by analysis of variance and continued with the Least Significant Difference (LSD) test at the 5% level. The correlation between C-organic, soil pH, soil temperature, soil moisture content, stalk dry weight, and weight of corn kernels with C-mic was tested by correlation test. The results showed that the application of humic acid and P fertilization had no significant effect on C-mic, and there was no interaction between the two at 7 days after planting (DAP), 56 DAP, and 104 DAP. There was a correlation between soil organic carbon at 7 DAP, 56 DAP, and 104 DAP, soil moisture content at 7 DAP, soil pH at 56 DAP and 104 DAP, soil temperature at 104 DAP, stalk dry weight at 55 DAP, corn kernels weight at 113 DAP with C-mic.
