Interactive Effects of Biochar and Phosphorus Fertilizer on PhoD-Harboring Bacteria and Phosphorus Dynamics in Moso Bamboo Forest Soil

Phosphorus (P) limitations in forest ecosystems have hindered sustainable development. The improvement in P availability with biochar has been widely studied in agroecosystems. However, the effects of biochar amendment on soil P dynamics and microbial properties have not been well documented in forest ecosystems, especially in Moso bamboo forest soil. A pot experiment was conducted to investigate the interactive effects of bamboo biochar (0, 10 g kg(-1)) and P fertilizer (0, 36 mg kg(-1)) on available P and P fractions on days 7 and 180 after fertilization. The phoD-harboring bacterial community structure and the activities of acid and alkaline phosphatases were analyzed via 16S rDNA sequencing and colorimetric methods, respectively. The results indicated that the application of P fertilizer and its co-application with biochar significantly enhanced soil P availability and inorganic P fractions (Al-P and Fe-P). However, bamboo biochar alone had no effect. The bamboo biochar amendment significantly increased the activities of acid and alkaline phosphatase compared to no P fertilizer application or biochar amendment. Redundancy analysis (RDA) revealed that the extractable K+ and Ca2+ were the most dominant contributors to the distribution of phoD-harboring bacterial community structure. Correlation analyses further indicated that Bradyrhizobium and Pseudomonas could play a key role in dissolving inorganic P, and Streptomyces, Amycolatopsis, and Cupriavidus in mineralizing organic P. The co-application of P fertilizer and biochar could be generally more beneficial for improving soil P availability in Moso bamboo forest soil.