Bacterial population and several soil properties across different vegetation stands in Andisols profiles at Mount Merbabu National Park, Indonesia

A fundamental understanding of the forest stands and upland farming practices is imperative for effective land management, as it impacts the several soil properties. This research was to evaluate the relationship of bacterial population and several soil properties across different vegetation stands in Andisols soil profiles. Soil sampling was conducted on Mount Merbabu National Park (puspa (Schima noronhae Theaceae) and pine (Pinus merkusii Pinaceae)) and upland farming. For each vegetation observation plot unit, a pedon was created and 3 replications were carried out; and each pedon was sampled at soil profile depths 0-100 cm (0-10, 10-20, 20-30, 30-50, 50-70, and 70-100 cm) so 54 soil samples were obtained. The soil samples were then analyzed: bacterial population by the Spread Plate Count method, soil pH by pH meter, soil organic matter (SOM) by Walkley and Black method, and soil moisture by gravimetric method. The results showed that puspa had the highest means bacterial population (19.9 ± 2.67 ×10⁷ CFU g⁻¹), SOM (8.24 ± 1.06 %) and soil moisture (29.71 ± 1.93 %) which were significantly different from pine and upland farming; the highest bacterial population and SOM content in each stands was produced in the top layer (0-10 cm) and decreases with increasing soil depth; the lowest soil moisture was obtained in the top layer and increases with increasing soil depth; and bacterial population had a very significant relationship and are positively correlated with SOM and negatively correlated with soil moisture.