Quantifying long-term soil phosphorus dynamics: a data assimilation approach
Abstract
Quantifying long-term (i.e. seasons or longer) soil phosphorus (P) dynamics is fundamentally important for the reliable evaluation of long-term soil P availability. Here, we constructed a processes-based soil P transformations model to describe long-term soil P dynamics. By fusing this model with eight datasets of 14-crops-driven changes in Hedley P fractions in greenhouse environments, we quantified the turnover and transformation rates of all major P pools of eight soils that varied largely in physiochemical properties, using a data assimilation approach. The performance of our model was better for labile P, secondary mineral P, and occluded P than for non-occluded organic P and primary mineral P. All parameters describing soil P dynamics were approximately constrained by the datasets. Correlations among model parameters indicated a close linkage among dynamics of labile P, non-occluded organic P, and secondary mineral P. Labile P amount was most sensitive to its turnover rate among parameters in all soils. The averaged turnover rates were: labile P (0.040 g g-1 d-1), non-occluded organic P (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 organic P (0.0066 g g-1 d-1), and occluded inorganic P (0.0065 g g-1 d-1). Both the turnover and transformation rates of all P pools varied across soils. Some of the parameters were significantly related to soil pH, organic C concentration, clay content, and/or plant P uptake. Our study demonstrated the potential of data assimilation in contributing to a quantitatively understanding of long-term soil P dynamics.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B41K2869H
- Keywords:
-
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0470 Nutrients and nutrient cycling;
- BIOGEOSCIENCESDE: 0486 Soils/pedology;
- BIOGEOSCIENCES