A global dataset on phosphorus in agricultural soils

Area of Science:

• Agricultural Science
• Soil Science
• Environmental Science

Background:

• Global soil phosphorus (P) distribution is influenced by farming, erosion, land-use change, and soil biogeochemistry.
• Previous models (GPASOIL-v0) combined global datasets with process models to estimate soil P dynamics.
• Understanding soil P distribution is crucial for sustainable agriculture and environmental management.

Purpose of the Study:

• To update the GPASOIL model (GPASOIL-v1) by incorporating recent advances in soil inorganic P dynamics, updated driver datasets, and regional soil P measurements.
• To improve the transparency and reproducibility of simulating agricultural soil P maps.
• To provide updated global estimates of soil P distribution in croplands and grasslands.

Main Methods:

• Revised an existing approach (GPASOIL-v0) by integrating updated global datasets on drivers of soil P distribution.
• Incorporated recent scientific understanding of soil inorganic P dynamics.
• Utilized regional soil P measurements for benchmarking and validation.

Main Results:

• Estimated global average inorganic labile phosphorus (P) in 2018: 187 kg P ha⁻¹ for cropland and 91 kg P ha⁻¹ for grassland (top 0-0.3m).
• Results showed sensitivity to organic P pool mineralization rates.
• Uncertainty in driver estimates resulted in coefficients of variation of 0.22 for cropland and 0.54 for grassland.

Conclusions:

• The updated GPASOIL-v1 model offers more transparent and reproducible methods for simulating agricultural soil P maps.
• Increased confidence in the new P estimates compared to previous versions.
• Further improvements are needed, as indicated by evaluations against regional datasets.