| 摘 要： |
Purpose The turnover of organic phosphorus (P-o) may be an important way to maintain P supply for plant growth under the phosphorus (P) deficiency in highly weathered tropical soils. However, there is limited information on P-o change pattern and how abiotic and biotic factors influence P-o transformation in tropical region. Thus, this study was aimed to the characteristics and controls of P-o transformation towards the advanced stage of tropical soil evolution. Methods A well-establish tropical soil chronosequence (0.09, 0.146, 0.64, 1.12, 1.81, and 2.30 million years) derived from basalt in northern Hainan Island, China, was selected and the P-o compounds in all soils determined by solution P-31 nuclear magnetic resonance spectroscopy. Results Phosphate monoester showed a rapid increase in the earlier stage of pedogenesis (< 0.15 million year), thereafter declined to the minimum in the 1.12-million-year site and fluctuated in older soils. Meanwhile, the proportion of labile P-o (including phosphate diester and its degradation products) increased continuously across the chronosequence, suggesting that long-term tropical soil evolution promoted labile P-o accumulation that was vital to maintain P supply in highly weathered and P-deficient soil. Redundancy analysis revealed that P-o transformation was jointly affected by soil total nitrogen, total organic carbon, phytase, and amorphous iron, accounting for 37.5% (p < 0.01), 29.5% (p < 0.01), 20.7% (p < 0.05), and 14.8% (p < 0.05) of explanation in the variations of P-o compounds, respectively. Conclusion Our study has supplemented the blank of P-o transformation during tropical soil evolution over a 2.30-million-year time scale and emphasizes the important role of soil C, N in regulating P-o changes. |
在线留言
联系我们
所长信箱