College of Environmental Science, Sichuan Agricultural University, Chengdu, 611130, China.
Soil and Water Sciences Department, University of Florida, Gainesville, FL, 32611, USA.
Chemosphere. 2019 Jun;225:311-319. doi: 10.1016/j.chemosphere.2019.03.069. Epub 2019 Mar 11.
Biochar can affect the phosphorus (P) cycle in the rice ecosystem through various pathways. Pot experiments were conducted to investigate the risk of P contamination and the P supply rate to crops with the application of maize straw-derived biochar (BM) and P fertilizer. The biochar increased 18.3% and 8.45% total phosphorus (TP) concentration in the low-P level and high-P level soils, respectively. The addition of biochar increased the phosphorus activation coefficient (PAC) by 9.00% at low-P levels, while the PAC was reduced by 10.4% at high-P levels. The results suggested that biochar could serve as either a source or a sink for P. The P concentration in the dithionite-citrate-bicarbonate (DCB) extracts on the root surfaces in biochar-treated soils increased by 467.1% and 46.1% in the low-P level and high-P level soils, respectively. It may cause by the acidification of soils near the root and the increase in Fe plaque. The results also showed the addition of biochar increased the DCB-P concentration and subsequently promoted rice growth. The biochar additions enhanced bacterial community richness and diversity, while the P supplementations inhibited bacterial growth. Redundancy analysis (RDA) showed that available nitrogen (AN), Fe-P, Ca-P, P uptake and, DCB extracted Fe (DCB-Fe) were significantly correlated with microbial community composition and explained 46.8%, 37.1%, 38.0%, 37.5% and 36.7% of the total community variability, respectively. This study provided evidence that biochar might affect the P cycle by impacting the microbial community composition and the Fe-reducing processes in the rice ecosystem.
生物炭可以通过多种途径影响水稻生态系统中的磷（P）循环。通过田间试验研究了玉米秸秆生物炭（BM）和磷肥的应用对低磷和高磷土壤中 P 污染风险和作物供 P 率的影响。生物炭分别增加了低磷和高磷土壤中总磷（TP）浓度 18.3%和 8.45%。在低磷水平下，生物炭增加了磷活化系数（PAC）9.00%，而在高磷水平下，PAC 降低了 10.4%。结果表明，生物炭既可以作为 P 的源，也可以作为 P 的汇。在生物炭处理土壤中，低磷和高磷土壤根表面二硫代苏糖醇-柠檬酸-碳酸氢盐（DCB）提取物中的 P 浓度分别增加了 467.1%和 46.1%。这可能是由于根附近土壤酸化和铁斑的增加所致。结果还表明，添加生物炭增加了 DCB-P 浓度，从而促进了水稻生长。生物炭的添加增加了细菌群落的丰富度和多样性，而 P 的补充抑制了细菌的生长。冗余分析（RDA）表明，有效氮（AN）、Fe-P、Ca-P、P 吸收和 DCB 提取的 Fe（DCB-Fe）与微生物群落组成显著相关，分别解释了总群落变异性的 46.8%、37.1%、38.0%、37.5%和 36.7%。本研究提供的证据表明，生物炭可能通过影响微生物群落组成和水稻生态系统中的 Fe 还原过程来影响 P 循环。
