College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
College of Natural Resources and Environment, Anhui Science and Technology University, Chuzhou, 233100, People's Republic of China.
Sci Rep. 2023 Jul 10;13(1):11122. doi: 10.1038/s41598-023-38369-2.
Identification and quantification of different soil phosphorus (P) fractions level are important for improving agricultural productivity and developing sustainable management practices in these agricultural soils under long-term cultivation. However, few studies have been conducted to investigate P fractions level and their transformation in these soils. This study was conducted to characterize P fractions as affected by different paddy cultivation ages (200, 400-yr and 900-yr) among soils of the Pearl River Delta Plain in China. A sequential chemical fractionation scheme and P nuclear magnetic resonance spectroscopy (P NMR) were employed to quantify various P fractions and speciation. Results showed soil easily-labile P, moderately-labile P and non-labile P had a positive relationship with total P (TP) and available P (AP). Analysis with P NMR spectroscopy revealed that inorganic P including orthophosphate (Ortho-P) and pyrophosphate (Pyro-P) increased with cultivation age, while organic species monoester phosphate (Mono-P) and diester phosphate (Diester-P) decreased. Moreover, acid phosphatase (AcP), neutral phosphatase (NeP), exchangeable Ca and sand contents are the main factors that affected the transformation of soil P composition, and non-labile P (Dil.HCl-Pi) and Pyro-P had significant contribution to soil P availability by affecting P activation coefficient. Therefore, long-term paddy cultivation, influenced by these soil parameters including NeP, AcP, exchangeable Ca and sand, accelerated the transformation of soil organic P/non-labile P to inorganic P.
不同土壤磷（P）形态的鉴定和量化对于提高农业生产力和发展这些农业土壤的可持续管理实践至关重要。然而，对于这些土壤中 P 形态及其转化的研究很少。本研究旨在研究中国珠江三角洲平原不同水稻种植年限（200 年、400-900 年）对土壤磷形态的影响。采用连续化学分级方案和磷核磁共振波谱（P NMR）定量分析各种磷形态及其形态。结果表明，土壤易解磷、中解磷和难解磷与总磷（TP）和有效磷（AP）呈正相关。P NMR 光谱分析表明，无机磷包括正磷酸盐（Ortho-P）和焦磷酸盐（Pyro-P）随种植年限的增加而增加，而有机磷单酯磷酸盐（Mono-P）和二酯磷酸盐（Diester-P）则减少。此外，酸性磷酸酶（AcP）、中性磷酸酶（NeP）、交换性钙和砂含量是影响土壤 P 组成转化的主要因素，非解磷（Dil.HCl-Pi）和焦磷酸盐通过影响 P 活化系数对土壤 P 有效性有显著贡献。因此，长期的水稻种植，受 NeP、AcP、交换性钙和砂等土壤参数的影响，加速了土壤有机磷/难解磷向无机磷的转化。
