Phosphorus budget in topsoils

Phosphorus (P) is an important nutrient for all plant growth and it has become a critical and often imbalanced element in modern agriculture. A proper crop fertilization is crucial for production, farmer profits but also for ensuring sustainable agriculture. The European Commission has published the Farm to Fork (F2F) Strategy in May 2020, in which the reduction of the use of fertilizers by at least 20% is among one of the main objectives. Therefore, it is important to look for the optimal use of P in order to reduce its pollution effects but also ensure future agricultural production and food security. It is essential to estimate the P budget with the best available data at the highest possible spatial resolution.

We develop an accounting framework by an Empirical Model for Phosphorus Balance (EMPBa) to estimate the phosphorus budget in the European Union topsoils.

Phosphorus budget = P_MinFert + P_Man + P_Atm + P_Che – P_Grain – P_Res – P_Eros    
With four phosphorus (P) inputs to soils:
•    P_MinFert is the P mineral fertilizer input;
•    P_Man the P manure input;
•    P_Atm the P atmospheric deposition;
•    P_Che the P deposition due to chemical weathering;
The three P outputs are:
•    P_Grain the P output from crop harvesting;
•    P_Res the P output with crop residue removal;
•    P_Eros the P losses with water erosion;

 

Inputs

The main P inputs are fertilizers,  manure application and input from atmospheric deposition and chemical weathering. In the EU and UK, the annual P inputs (from inorganic fertilizers, manure, atmospheric deposition, and chemical weathering) to agricultural soils were around 2.74 Million tonnes (Mt) with an uncertainty of ±13.5%. This amount corresponds to a mean input of 16±2 kg P ha-1 yr-1, with inorganic fertilizers and manure input contributing 48% each to the total P inputs in agricultural soils. Atmospheric deposition and chemical weathering were a small fraction of total input with 3.5% and 0.5%, respectively.

P inputs by organic fertilizers. Between 2011-2019, the average mineral P input with fertilizers was 7.6±0.8 kg P ha-1 yr-1, with the Netherlands, Estonia, and Sweden having the lowest P rates in agricultural lands (< 4 kg P ha-1 yr-1) and, Italy, Spain, Croatia, and Poland highest P mineral inputs (> 9 kg P ha-1 yr-1). In the Eastern European countries, the mean P fertilizer input is less than 7 Kg P ha-1 yr-1, with the exception of Slovenia and Poland. Summing up the P input in agricultural soils of the EU and UK with inorganic fertilizers, we estimate a total of 1.31 Mt P yr-1

P inputs with manure application. In the EU and UK, more than 1.4 billion tonnes yr−1 of manure are generated, of which more than 90% is directly re-applied to soils as organic fertilizer in agricultural lands.The mean P organic input in the EU and UK was about 7.6±1.4 kg P ha-1 yr-1, with the Netherlands, Belgium, Denmark, and Ireland having the highest rates (> 15 kg P ha-1 yr-1), while Baltic States, Scandinavia, and Bulgaria (< 2.5 Kg P ha-1 yr-1) having the lower rates, followed by Eastern European countries such as Slovakia, Czechia, and Hungary (< 3.8 kg P ha-1 yr-1).  Cumulative, the annual organic P input with manure was estimated to be about 1.31 Mt, similar to the P inputs with inorganic fertilizers. The estimated uncertainty based on the variability of animal excretion rates is at ±17.3%.

Atmospheric deposition & chemical weathering. The P inputs from atmospheric depositions for the study area are ca 99 Kt P yr-1. The chemical weathering contributes with ca. 15 kt P yr-1 .

Outputs

The main P outputs are crop harvesting, residues removal and losses by soil erosion. Specifically, we attempt to estimate the P removal by taking into account the production area and productivity rates of 37 crops for 220 regions in the European Union (EU) and the UK. To estimate the P removal by crops, we include the P concentrations in plant tissues (%), the crop humidity rates, the crop residues production, and the removal rates of the crop residues.

The total P removal is about 2.61 Mt  (±260 Kt) per year with crop harvesting having the larger contribution (c.a. 94%) compared to the crop residues removal. A Monte-Carlo analysis allows to  estimate a ±9% uncertainty. In addition, we performed a projection of P removal from agricultural fields in 2030. By providing this picture, we aim to improve the current P balances in the EU and explore the feasibility of F2F objectives.

Crop production in EU: The annual crop production in the European Union (EU) and the UK in 2016 added up to approximately 300 million tones (Mt) of cereals cultivated in 57 million ha (mean 5.3 t ha-1), 33 Mt oilseeds cultivated in 12.5 million hectares (Mha) (mean 2.6 t ha-1), 185 Mt of other arable crops, 93 Mt of vegetables cultivated in 2.6 Mha, 665 Mt of fodder crops (mean 31.4 t  ha-1), 70 Mt of fruits (mean 6 t  ha-1) and 1,280 Mt of grass production.

P removal with crop harvesting: In the EU and the UK, the total P removed with harvested crops is about 2.4 Mt per year with an uncertainty of ±8.8% at a 90% confidence level.  The quantity of P removed with harvesting crops varies in the range of 2.19-2.6 Mt. The mean removal with crop harvesting is about 14 kg P ha-1 yr-1 with an uncertainty of 1.2 kg P ha-1 yr-1. In absolute terms, the three countries with the highest agricultural production (Germany, France, and the UK) cover ca. 1/3 of the 180 Mha of agricultural lands, while their P plant removal is 47% of the total (ca. 1.11 Mt of P). On the contrary, the larger Mediterranean countries (Spain, Italy, Portugal, and Greece) occupy ¼ of the total agricultural land but have a P removal of only ca.15% of the total. The mean P removal by crop harvesting is 16 kg ha-1 yr-1 in cereals, 15.2 kg ha-1 yr-1 in oilseeds, 38 kg ha-1 yr-1  in vegetables, 13 kg ha-1 yr-1 in fodder crops and pastures, and 2 kg ha-1 yr-1 in fruits.

P removal with plant residues: The total crop residues produced from agricultural lands are estimated to be about 353 Mt (max. 395 Mt) per year with the cereals producing the major part of it (circa 292Mt ±25 Mt). The results show that 130 Mt of dry matter crop residues per year are  removed each year in the EU27 and UK.The total P removal by crop residues is about 151 thousand tonnes (Kt) with ±14% uncertainty at a 90% confidence level.

P losses due to erosion: The total P losses to river basins and sea outlets were about 66 kt of P per year corresponding to about 0.35 kg P ha-1 yr-1. In case we consider the enrichment of sediments, the total P losses to river basins and sea outlets would increase to 97 kt of P per year, increasing the mean P loss to 0.5 kg P ha-1 yr-1.

Total P removal: By summing up the P removal with crop harvesting and residues, we estimate a total P uptake of 2.61 Mt with an uncertainty of ±0.26 Mt per year. Most of the North-West EU regions (North France, Ireland, Belgium, Germany, Netherlands and Denmark) have a mean P removal higher than 22 kg ha-1 yr-1(Fig below). In the Mediterranean countries this rate is less than 11 kg ha-1 yr-1 while the Eastern EU countries are varying in the range of 13-17 kg ha-1 yr-1

Phosphorus Budget

A positive value (surplus) represents a potential loss to the environment or accumulation in the soil, while a negative value indicates a deficit (i.e., soil nutrient depletion). In the 171,000 ha of agricultural land in the EU and UK, the P surplus was estimated to be about 130 kt of P. Uncertainty accounts for ±370 kt of P in the inputs and ±260 kt in outputs. For the whole study area, we estimate a P surplus of 0.8 kg P ha-1 yr-1, with an uncertainty of ±3.5 kg P ha-1 yr-1 and a range from -2.7 to +4.3 kg P ha-1 yr-1. We also estimated the P budget at national scale, with Italy, Spain, Netherlands, Belgium, Portugal, Greece, Poland, Slovenia, Croatia, Malta and Cyprus having a mean national surplus higher than 4 kg P ha-1 yr-1 . Contrary, Germany, Sweden, Finland, Estonia, Lithuania, Latvia Czechia, Slovakia, Austria and Bulgaria have a mean P deficit higher than 3 kg P ha-1 yr-1. Ireland and Romania have very low surplus (close to 0), Denmark has a mean surplus of 2.6 kg P ha-1 yr-1, while France, Hungary and UK have a low mean deficit of circa 2 kg P ha-1 yr-1 . At national scale, the uncertainties were lower than 18% in Greece, Italy, Spain, and Poland (Supplementary material Fig. S5) but relatively high (>38%) in the Netherlands, Ireland, Denmark, Estonia, and Latvia .

Among the 223 regions, 24 regions had a neutral status (neither P surplus nor deficit). Their average P budget ranged between -1 and 1 kg P ha-1 yr-1 . In 78 regions, mainly in Scandinavia, Baltic States, and Central and partially in Western Europe, we estimated a P deficit higher than 1 kg P ha-1 yr-1. The majority of the regions (121) have a surplus of P (Fig. 9) and most of those are in Mediterranean countries, Poland, Denmark, western France, Slovenia, and Croatia. In some cases, like France, the subnational surpluses in the North-western part are quite different from national averages.

 

Data available: Get the full data package for:

a) Shapefiles for P inputs (fertilizers, manure, chemical weathering, atmospheric deposition) and the losses by water erosion.

b) The P budget and the P inputs/ouptus are available at NUTS2 (Regional scale) and country scale.

c) Total P concentration (GeoTiff) and the P available / Total P stocks in EU agricultural soils.

d) 21,681 LUCAS point data with Total P (csv, shapefiles) (update Feb 2023).

Reference:

Panagos, P., Köninger, J., Ballabio, C., Liakos, L., Muntwyler, A., Borrelli, P. and Lugato, E., 2022. Improving the phosphorus budget of European agricultural soils. Science of The Total Environment, 853: 158706. DOI: 10.1016/j.scitotenv.2022.158706

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In addition, you can get the P output data available: Shapefiles for P uptake with crop harvesting , Mean P removal due to crop harvesting per crop and crop category , P removal with crop residues , Total P output (crop harvesting + plant residues)

Reference:

Panagos, P., Muntwyler, A., Liakos, L., Borrelli, P., Biavetti, I., Bogonos, M. and Lugato, E., 2022. Phosphorus plant removal from European agricultural land. Journal of Consumer Protection and Food Safety, 17: 5-20. DOI: 10.1007/s00003-022-01363-3

 

 

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Title: Phosphorus cycle in European agricultural soils
Resource Type: Datasets, Soil Functions Data
Theme/Sub-Theme: Soil Nutrients, Phosphorus budget in topsoils
Registration requested: Request Form
Continent:
Year: 2024
Keywords: Phosphorus |