Study area: We cover 1.04 billion ha of global cropland with a resolution of 0.5°×0.5° based on the land-use harmonization data.
Soil phosphorus (P) loss from agricultural systems will limit food and feed production in the future. Here, we combine spatially distributed global soil erosion estimates (only considering sheet and rill erosion by water) with spatially distributed global P content for cropland soils to assess global soil P loss. The world’s soils are currently being depleted in P in spite of high chemical fertilizer input. Africa (not being able to afford the high costs of chemical fertilizer) as well as South America (due to non-efficient organic P management) and Eastern Europe (for a combination of the two previous reasons) have the highest P depletion rates. In a future world, with an assumed absolute shortage of mineral P fertilizer, agricultural soils worldwide will be depleted by between 4–19 kg ha−1 yr−1 , with average losses of P due to erosion by water contributing over 50% of total P losses.
The main loss of phosphorus from agricultural soils is due to soil erosion. Thus we combine the most recent spatially distributed global soil erosion estimates with global P content of cropland soils to assess global soil P loss maps. Global soil phosphorus contents were taken from Ringeval et al. 2017. Phosphorus loss from soils was induced by erosion/ soil loss. The data on soil erosion were taken from Borrelli et al. 2017.
As a result, the world’s soils are currently being depleted in Phosphorus in spite of high chemical fertilizer input. The P depletion rates are different from continent to continent.
Global average phosphorus (P) losses due to soil erosion in kg ha−1 yr−1.
Global P soil pools and depletion due to erosion.
Arrows indicate fluxes (positive: net input to soils, negative: depletion of soils). *Organic P management = sum of manure and residue input minus plant uptake.
Nonplant P = non-plant available P. Inorganic and organic P give plant available fractions.
Total soil P: sum of P fractions lost from soil via erosion with
relative errors. No/ with chemical =P balance with and without chemical fertilizer.
Soil P pools and depletion due to erosion in Africa, Europe and North America.
AD = Atmospheric Deposition. CF = Chemical Fertilizer.
OM= Organic P management = sum of manure and residue input minus plant uptake. Arrows indicate fluxes (positive: net input to soils, negative: depletion of soils). Non-plant P = non-plant available P. Inorganic and organic P give plant available fractions. Soil Plost: sum of P fractions lost from soil via erosion with relative errors. No/with chemical= P balance with and without chemical fertilizer.
Please follow this link to download the data both on "Global average P losses due to soil erosion in kg P ha-1 yr-1" and on Global P pools and fluxes.
Alewell, C., Ringeval, B., Ballabio, C., Robinson, D.A., Panagos, P., Borrelli, P. 2020. Global phosphorus shortage will be aggravated by soil erosion. Nat Commun 11, 4546. https://doi.org/10.1038/s41467-020-18326-7
References - Input data:
Ringeval, B. et al. 2017. Phosphorus in agricultural soils: drivers of its distribution at the global scale. Global Change Biology, doi:10.1111/gcb.13618 .
Borrelli, P. et al. 2017. An assessment of the global impact of 21st century land use change on soil erosion. Nature Communications 8, 2013, doi:10.1038/s41467-017-02142-7.