A soil phosphorus dynamics (SPD) model

The dynamics of soil phosphorus (P) control its bioavailability. Yet, it remains a challenge to quantify soil P dynamics. Here, we developed a soil P dynamics (SPD) model. We then assimilated eight datasets of 426-day changes in Hedley P fractions into the SPD model, to quantify the dynamics of six major P pools in eight soil samples that are representative of a wide type of soils. The performance of our SPD model was better for labile P, secondary mineral P, and occluded P than for non-occluded organic P (Po) and primary mineral P. All parameters describing soil P dynamics were approximately constrained by the datasets. The average turnover rates were labile P 0.040 g g^-1 d^-1, non-occluded Po 0.051 g g^-1 d^-1, secondary mineral P 0.023 g g^-1 d^-1, primary mineral P 0.00088 g g^-1 d^-1, occluded Po 0.0066 g g^-1 d^-1, and occluded inorganic P 0.0065 g g^-1 d^-1, in the greenhouse environment studied. Labile P was transferred on average more to non-occluded Po (transfer coefficient of 0.42) and secondary mineral P (0.38) than to plants (0.20). Soil pH and organic C concentration were the key soil properties regulating the competition for P between plants and soil secondary minerals. The turnover rate of labile P was positively correlated with that of non-occluded Po and secondary mineral P. The pool size of labile P was most sensitive to its turnover rate. Overall, we suggest data assimilation can contribute significantly to an improved understanding of soil P dynamics.

土壤磷（P）的动态过程决定其生物有效性，然而量化土壤磷动态仍是一项挑战。本研究构建了土壤磷动态模型（soil P dynamics model, SPD），随后将涵盖426天变化的8组Hedley磷分级（Hedley P fractions）数据集同化至该模型中，以量化8个具有广泛代表性土壤样本内6种主要磷库的动态变化。相较于非闭蓄态有机磷（non-occluded organic P, Po）与原生矿物态磷（primary mineral P），本SPD模型对活性磷（labile P）、次生矿物态磷（secondary mineral P）及闭蓄态磷（occluded P）的模拟效果更优。所有表征土壤磷动态的参数均被数据集大致约束。在本研究的温室环境中，各磷库的平均周转速率分别为：活性磷0.040 g·g⁻¹·d⁻¹，非闭蓄态有机磷0.051 g·g⁻¹·d⁻¹，次生矿物态磷0.023 g·g⁻¹·d⁻¹，原生矿物态磷0.00088 g·g⁻¹·d⁻¹，闭蓄态有机磷（occluded organic P, Po）0.0066 g·g⁻¹·d⁻¹，闭蓄态无机磷（occluded inorganic P）0.0065 g·g⁻¹·d⁻¹。活性磷的平均迁移去向以非闭蓄态有机磷（迁移系数0.42）与次生矿物态磷（0.38）为主，仅有0.20的比例被植物吸收利用。土壤pH与有机碳浓度是调控植物与土壤次生矿物间磷竞争的关键土壤属性。活性磷的周转速率与非闭蓄态有机磷、次生矿物态磷的周转速率呈正相关。活性磷的库容量对其自身周转速率最为敏感。综上，本研究表明数据同化技术可显著助力对土壤磷动态过程的深入理解。

搜集汇总

背景与挑战

背景概述

该数据集提供了一个土壤磷动态（SPD）模型，用于量化土壤中六种主要磷库的动态变化，基于同化8个包含426天Hedley磷组分变化的数据集，覆盖八种代表性土壤样本。模型在易变磷、次生矿物磷和闭蓄磷方面表现较好，并揭示了土壤pH和有机碳浓度是调节磷竞争的关键因素，有助于通过数据同化方法提升对土壤磷动态的理解。