Phosphorus balance in agriculture

From Statistics Explained

Data from September 2011. Most recent data: Gross Nutrient Balance

This article presents recent statistics on the the gross phosphorus balance in agriculture at the level of the European Union (EU), its Member States and some of the EFTA countries.

The gross phosphorus balance provides an insight into the links between agricultural phosphorus (P) use, losses of P to the environment, and the sustainable use of soil P resources. The gross phosphorus balance indicates the total potential risk to the environment (water and soil). The actual risk depends on many factors including climate conditions, soil type and soil characteristics, soil P saturation, management practices such as drainage, tillage, irrigation etc. Additional information on the vulnerability of the soil to P leaching and run-off is necessary to assess the risk of P to water.

Figure 1: Gross phosphorus balance, 2000-2008 (kg P per ha agricultural land)
Source: Eurostat (aei_pr_gnb)
Figure 2: Total phosphorus inputs, average 2005-2008 (kg P per ha agricultural land)
Source: Eurostat (aei_pr_gnb)
Figure 3: Share in total phosphorus inputs, average 2005-2008 (%)
Source: Eurostat (aei_pr_gnb)
Figure 4: Share of livestock in total phosphorus manure production, average 2005-2008 (%)
Source: Eurostat (aei_pr_gnb)
Figure 5: Total phosphorus outputs, average 2005-2008 (kg P per ha agricultural land)
Source: Eurostat (aei_pr_gnb)
Figure 6: Share in total phosphorus outputs, average 2005-2008 (%)
Source: Eurostat (aei_pr_gnb)

Main statistical findings

Gross phosphorus balance trends

Most countries reduced the gross phosphorus balance per ha in the period 2005-2008

Between 2005 and 2008, the gross phosphorus balance for the EU-27 remained relative stable with an estimated average of 2 kg phosphorus (P) per ha. In the EU-15 the gross phosphorus balance reduced slightly from an estimated average of 5 kg P per ha in the period 2000-2004 to an estimated average of 3 kg P in the period 2005-2008. In the ten Central and Eastern European countries (CEC) which joined the EU in 2004 and 2007 (PL, SI, SK, EE, LT, LV, CZ, HU, RO and BG - see country codes) the gross phosphorus balance was much lower than in the EU-15, with an estimated average of 0 kg/ha over the period 2005-2008.

The gross phosphorus balance is high in the Mediterranean islands MT and CY and Northwest-Europe (NO, NL, UK, DK) while the balance is negative for IT and EL and many of the Central and Eastern Member States (CEC). Figure 1 shows the average gross phosphorus balance per hectare of agricultural land (the total of arable land, land under permanent crops and permanent grassland) for the periods 2000-2004 and 2005-2008. The gross phosphorus balance per ha decreased in most countries in 2005-2008 compared to 2000-2004, exceptions were PL and NO. Data for CY and EE were not available for 2000-2004.

Phosphorus inputs

Many of the countries with a high average phosphorus surplus between 2005 and 2008 also have a relative high P input per ha (for instance NL, MT), see Figure 2. A high input does however not necessarily lead to a high phosphorus balance, as the balance is also determined by the output. The phosphorus input per ha of BE in 2005-2008 (estimated at 35 kg P per ha) for instance is higher than that of NO (estimated at 26 kg P per ha), but due to a much higher P output per ha the P surplus of BE (estimated at 6 kg P per ha) is less than half of the P surplus of NO (estimated at 15 kg P per ha).

Fertilisers

Inorganic fertilisers and manure account for more than 95 % of the P input in the EU-27 between 2005 and 2008. At the moment the re-use of P through the use of compost, sewage sludge, industrial waste etc is at the moment insignificant. Data on other organic fertilisers are however lacking in many countries, therefore the significance of these fertilisers could be underestimated.

The choice of fertiliser type (manure, mineral fertilisers, other organic fertilisers) has different impacts on the environment:

  • The P in manure and fertilisers is not available to the plant in the same rate for different types of manure and fertilisers.
  • The production of P fertilisers contributes to GHG emissions (though some studies show a net GHG emissions benefit for certain production techniques).
  • Mineral P fertilisers are produced from natural resources which are limited available and depleting. Haes et all estimated that reserves which currently can be economically extracted to be depleted in 70-100 years and reserve bases which currently cannot be economically extracted to be depleted between 170-264 years depending on growth in P-consumption[1]. Without the application of mineral fertilisers the current level of agricultural production cannot be sustained.
  • Other potential fertilisers like urban wastes often include health hazards (to both plants and humans) and procedures commonly used to reduce these hazards - such as composting - tend to reduce the fertiliser value.

Manure input

The share of manure in total inputs is on average for 2005-2008 smaller in the Central and Eastern Member States (CEC) (46 %) than in the EU-15 (55 %). Manure withdrawals and imports are only of significance (>5 % of total manure production) in a very few countries (BE, NL, HU). This means that for most countries the manure used is mainly determined by the amount of manure produced in the country. The manure production in kg P per ha is twice as high on average in the EU-15 as in the Central and Eastern Member States (CEC) in the period 2005-2008. The manure production is determined by the amount and type of livestock in the country. In the EU (2007), MT, NL, BE, DK, CY and IE have the highest livestock densities and also belong to the countries with the highest rates of manure input per ha (>=15 kg P per ha). BG, LT, EE and LV belong to the countries with the lowest livestock densities and also belong to the countries with the lowest rates of manure input per ha (<5 kg P per ha). The countries with the highest livestock densities belong also to the countries with a high share of manure in total input (>=2/3).

The dependence on mineral fertilisers for P input is stronger in the CEC countries (51 % of total P input) than in the EU-15 (41 %) on average in 2005-2008. There are however big differences between countries; The share of inorganic fertilisers in total P inputs is larger than 50 % in HU, PL, IT, LV, ES, ES, EE, LT, while the share in the NL, BE, DK and MT is below 25 %. These figures should however be taken with care as the estimation of the P input of manure is largely depending on the excretion coefficients used to convert animal numbers in P manure production. For many countries these coefficients were not available and have been estimated by Eurostat.

Figure 4 shows that cattle contributes the most to P manure production and over 50 % in most countries except in DK (where pigs have the highest share), in CZ, PT, PL, MT, ES, HU, BG, RO, and CY (where different livestock types are important), and in EL (where sheep and goats have the highest share).

Phosphorus outputs

The removal of P with harvest and grazing of crops and forage per ha varies between crops and countries as can be seen in Figure 5. Grassland and cereals production have the highest P removal rates per ha, though great variation exists between countries due to differences in yields and P content per tonne of product. The P content per tonne product is among others depending on farmer practices like fertilisation, irrigation, mowing vs grazing etc.

The dominant share of total P output in the EU-27 (2005-2008) is the uptake of P with cereal production (36 %) and grassland (31 %), see Figure 6. P output is depending on cropping patterns, yields, farm management practices (tillage, irrigation etc), climate etc. The cropping pattern in 2007 showed that permanent and temporary grassland covered 39 % of the UAA in 2007 (38 % in 2005) and cereals 34 % (same as 2005). There are however significant differences between countries, in some countries (for example UK, SI, IE, NO) grassland dominates the UAA, where for instance in BG, HU and DK cereals are the dominating crop. Permanent crops are significant in Mediterranean countries.

Data sources and availability

Methodology

The P input and P output is estimated for each item of the balance by multiplying basic data (such as crop area, crop production, livestock numbers etc) with coefficients to convert the data into P contents.

All the figures in this article are presented as averages over a period of 5 years. Meteorological conditions have a big impact on the annual estimated gross phosphorus balances. The amount of nutrients removed with the harvest and grazing of crops and fodder, is depending on the nutrient content of crops and fodder and the yields of crops and fodder. The nutrient content of fodder and crops is estimated to be more or less constant in most countries. The amount of nutrients removed with the harvest and grazing of crops and fodder is therefore mainly depending on yields. Yields are depending on farmer practices (like pesticide and fertiliser use, irrigation etc) and on meteorological conditions. Metereological conditions vary significantly from year to year and these fluctuations can also be seen in the estimated nutrient output and surplus. In 2003 and 2007 for instance, large parts of Europe were hit by extreme weather causing significant drops in crop production, a peak in the balance can be noted for these years in some Member States. Variations in the nutrient surplus between years should therefore be interpreted with care. To limit the impact of metereological conditions on the trend, the trend can best be analysed looking at averages over a period of a few years.

Data availability

Data have been received, validated and approved from AT (1985-2009), CH (1990-2008), CZ (1985-2009), DE (1990-2008), EE (2004-2008), FI (1985-2009), HU (1990-2008), IE (1985-2009), NL (1985-2008), NO (1985-2009), PL (1985-2009), PT (1995-2008), SE (1985-2009), SK (1985-2009), DK (1985-2009) and the UK (1990,1995,2000-2009).

Data were not available and have been estimated by Eurostat for GR (1990-2008), LU (1990-2008), IT (1990-2008), SI (1995-2008), BG (2003-2008), RO (2003-2008), CY (2005-2008), LT (2005-2008), LV (2004-2008).

Due to methodological differences data have been estimated by Eurostat for BE (1990-2008), ES (1996-2008), FR (1990-2008).

Partial data was available for MT (crop production, livestock number, agricultural area). Eurostat has estimated the balances for MT (2002-2008) based on the data received by MT and other sources.

Data are available or have been estimated for the main inputs and outputs of the balance. These include: consumption of inorganic fertilisers, manure production of total livestock, removal of nutrients by the harvest of crops, removal of nutrients by the harvest and grazing of fodder.

Data are less available for: consumption of organic fertilisers (excluding manure), manure withdrawals, manure stocks, manure imports, seeds and planting material and atmospheric deposition of phosphorus.

Data sources

Inorganic fertilisers

Most countries use data based on sales and/or production and trade statistics. Some countries use farmer surveys. Data based on sales and/or production and trade statistics may be biased due to the inclusion of fertilisers not used in agriculture (private/public sector use, explosives, intermediate products etc). Reliability and accuracy of farmer surveys depend a.o. on the sampling design and size. For countries who did not submit data to Eurostat, data from Fertilisers Europe (see also Eurobase Consumption estimate of manufactured fertilisers (source: Fertilisers Europe) (aei_fm_manfert) ) have been used and of the FAO in the case of MT.

Other organic fertilisers

Data on organic fertilisers (excluding manure) are only available in a limited amount of countries (AT, BE, DE, ES, FI, IE, NL, SE, UK, CZ, HU, SK, CH, NO, DK). Available data show that other organic fertilisers are of some significance in some countries (>5 % of total P inputs average 2005-2008). Missing data on organic fertilisers may therefore lead to a minor underestimation of the balance in some countries.

Manure production

Manure production is estimated from animal numbers and excretion coefficients. Animal numbers should reflect the average amount of animals present during the year. Data on cattle, pigs, goats and sheep are available from European harmonised data sources such as the annual livestock statistics, the FSS and livestock registers. Livestock surveys may however not represent the average amount of animals well as they refer to a specific day, which means that offspring for instance may not be included very well, however a correction can be made in the excretion coefficients to take into account the offspring. For poultry and other livestock data is less available. Some poultry types and equidea are counted in the FSS, countries may have other data sources available to estimate poultry and other livestock types. The available data show that poultry is of significant importance in some countries (UK, SK, NL, FI, PT HU, CZ and PL >10 % of total P manure production, average 2005-2008), and other livestock is of minor significance in most countries (<5 % except in DK (6 %) HU (12%) and FI (11 %). Missing data on poultry and other livestock may therefore lead to an underestimation of the estimated balance for countries, where these livestock are significant.

As manure is a large input in the balance, excretion coefficients have a big impact on the final outcome. Excretion coefficients reported by the countries vary widely between countries, partly this reflects differences in farming practices and partly differences are caused due to the applied methodology and availability of data to calculate the coefficients. It is necessary to establish guidelines on the excretion coefficients to be used, to improve the transparency and the comparability of the balances between countries. Eurostat has estimated P excretion coefficients for countries (BE, BG, EL, ES, FR, IT, CY, LV, LT, LU, MT, RO and SI) where coefficients were not available (or in case of methodological issues), based on data supplied by the country and data of other countries. The reliability and accuracy of these estimations is limited. As manure is of significant importance to the final outcome, the reliability and accuracy of the balances estimated for these countries is also limited.

Manure withdrawals

Available data on manure withdrawals available show that manure withdrawals are significant in BE (Flanders region) and NL (ca 15 % of P manure production, in HU (20 %), while non-significant (<5 % of total manure production) in other countries (CH, NO, CZ, ES and AT). Most countries however do not have data or only limited data available on manure withdrawals, in the case when there are significant withdrawals this may lead to some overestimation of the manure input.

Change in manure stocks

None of the countries had data available on changes in manure stocks. Under normal circumstances it can however be assumed the change in manure stocks is on average zero, and therefore the effect of missing data on the balance is negliglible.

Manure imports

Data on manure imports were only available from CH, AT, NL, NO and BE (Flanders). Manure imports were insignificant (<3 % of total manure input) for these countries. Trade of manure occurs mainly from high surplus countries to neighboring countries. It is known that there are exports from for instance the Netherlands to France and Germany. It is likely that countries with a high nutrient surplus like Belgium and Denmark may export manure as well. The exact amounts which goes to which country are not available, however from the size of the exports of the Netherlands it can be assumed that the effect on the balance of Germany and France is very limited, the manure imports are likely to be less than 5 % of the total manure input.

Atmospheric deposition

Atmospheric deposition is estimated from landuse data and deposition rates. Some countries annually update deposition rates. Countries use different methodologies to estimate deposition rates (models, measurements, expert judgment, scientific research). Most countries do not have data available on P deposition. Available data (AT, DE, FI, IE, SE, UK, CZ, PL, SK, CH, NO) show that it is significant only in AT and CZ (>5 % of total inputs, average 2005-2008). For some countries where atmospheric deposition of P is of significance the exclusion of P deposition could therefore result in a minor underestimation of the P balance.

Seeds and planting materials

Data on seeds and planting material are not available from all countries. Data available show however that seeds and planting material are of minor inportance (<5% of total P input).

Harvested Crop production

Data on harvested crops are available from European statistics, the annual crop production statistics. Coefficients of nutrient contents of crop production vary between countries, partly this reflects differences in farming practices and climate and partly differences are caused due to the applied methodology (measurements, scientific research, expert judgements). It is necessary to review the coefficients used in relation to fertilizer and manure input and climate.

Crop residuals

Data on crop residuals removed from the field are limited available. Available data show that the share of crop residuals in total P output is negliglible (<2 %).

Fodder

The estimates of grassland production and consumption have a big impact on the balance outcome (31 % of total P output in the EU-27, average 2005-2008). At the moment approaches to estimate grassland production and consumption varies significantly between countries and the uncertainty in the estimates is significant. Grassland production includes fresh matter, grass silage, hay and grass grazed by ruminants. The yield and nutrient content of grassland can be estimated from measurements, scientific research, and expert judgements. Grassland consumption can also be estimated from a fodder balance, based on feed requirements and statistics on other feed. The estimation of grass grazed is particularly difficult. Data are in many countries only limited available (in respect with grassland areas and products taken into account). There is a need to improve the estimation of grassland production and consumption.

Reference Area

Data on arable land, land under permanent crops and permanent grassland are available from Eurostat Crop Statistics (landuse). In principle only potential fertilized areas should be included in the balance and very extensive areas should be excluded from the balance. Only the UK and CH have identified extensive areas and excluded these from the balance. A clear definition of the areas to be excluded from the balance is lacking. Improvement in the definition of the reference area is needed as well as the methodology to correct for agricultural production taking place on these areas.

Context

Gross phosphorus balances and the agri-environment

The gross phosphorus balance provides an insight into the links between agricultural phosphorus (P) use, losses of P to the environment, and the sustainable use of soil P resources. The gross phosphorus balance indicates the total potential risk to the environment (water and soil).

Sustainability could be defined by preserving and/or improving the level of production without degrading the natural resources. The P cycle can be described as follws: Initially P weathers form rocks to soil and soil water. Plants take up P to grow. Animals eat plants. With animal excretion and the death and decay of animals and plants P returns to the soil and soil water, and plants can use them again to grow etc. Some of the P in the soil and soil water however gets lost from this cycle through erosion and leaching and ends up in the ocean. In the ocean sediments are formed and after millions of years the sea floor rises and expose P to land. After more time the P weathers again from the rock to soil and soil water and this cycle starts again. Agriculture breaks this cycle as P is removed from the soil of the ecosystem with the harvest of crops for human and industrial purposes and the harvest of fodder and the grazing by livestock for livestock production. The P removed from the soil does not (or only partly) return to the soil of the ecosystem. Example: a part of the P in the crops consumed by humans ends up as human excretion in the sewage. Without replenishing the P removed, the soil looses its fertility as the P stock becomes depleted and plants need P to grow. Therefore, to sustain soil fertility and the growing and harvesting of crops and fodder, fertilisers and manure are need to be applied.

Before the industrial revolution the availability of P limited agricultural production, as the natural level of soil P is very low and limiting plant growth. The production of mineral fertilisers from phosphate rocks created a possibility to supply P to agricultural soils which did not originate from the area. This created an additional source of P, and a possibility to increase agricultural production without reducing soil fertility. This external application of phosphate (and other fertilizers) from external sources was one of the preconditions for the increase in the world population from approximately 1 billion people in 1850 to the current population of 6.8 billion[2]. The intensification of agriculture and the use of mineral fertilisers have however lead to environmental problems. Increased amounts of P supplied to the soil will potentially cause more P to be lost to water running over the soil surface or leaching through the soil. Loading soils with very high levels of phosphate will generally not hurt crops but may result in increased P movement to nearby bodies of water, resulting in pollution of drinking water and eutrophication of surface waters. It has been estimated that 25% or less of P applied annually is actually taken up by the growing crop, the remaining 75 % becomes bound in the soil profile or is lost to the water [3].

The gross phosphorus balance indicates the total potential risk to the environment (water and soil). The actual risk depends on many factors including climate conditions, soil type and soil characteristics, soil P saturation, management practices such as drainage, tillage, irrigation etc. Additional information on the vulnerability of the soil to P leaching and run-off is necessary to assess the risk of P to water.

An additional indicator is being developed to asses the vulnerability of the soil to P leaching and run-off.

Gross phosphorus balance and policies

International conventions of importance to phosphorus use in agriculture include inter alia MAP (Mediterranean Action Plan), CBD (Convention on Biological Diversity) and OSPAR (Oslo & Paris Convention to prevent pollution). Such international treaties often give an impetus to harmonise standards amongst all Member States of the European Union. Despite the significant off-site impact that diffuse contamination of phosphorus from agricultural land poses, there is no specific legislation that is directly concerned with the use of phosphorus in agriculture at the European level. However, aspects of the phosphorus problem are integrated in several policy areas and related legal instruments at the European level, for instance:

  • The Water Framework Directive (2000/60/EC) (WFD) is a legal obligation to protect and restore the quality of waters across Europe. Measures applied under the Water Framework Directive affecting the use of phosphorus in agriculture relate to best environmental practices and include the reduction of nutrient application, the modification of cultivation techniques, the proper handling of pesticides and fertilisers, and the prevention of soil erosion through erosion minimising soil cultivation. Most measures suggested in this context are aimed at reducing the influx of nutrients, such as nitrogen, phosphorus as well as pesticides to the groundwater as well as surface waters.The P balance surplus (every 6 years at level of water body catchment) is a commonly used indicator for identifying areas vulnerable to nutrient pollution in the pressures and impacts analysis.
  • The Nitrates Directive (91/676/EEC) (ND), established in 1991 aims to reduce water pollution caused or induced by nitrates from agricultural sources and prevent further such pollution. The Water Framework Directive explicitly refers to the Nitrates Directive for information on diffuse pollution of nitrates from agricultural activities and extends this to phosphates. The measures established within the Action Programmes aim to control diffuse and direct water pollution and also influence the use of phosphorus in farm practice. For instance, by limiting the annual application of nitrogen fertiliser and livestock manure, defining legally binding maximum concentrations of nitrates in drinking water and designating periods when the application is prohibited, the directive clearly aims at establishing and maintaining the natural balance of fertilisers in soils. Through these measures a massive influx of nutrients to ground- and surface water and thus potential eutrophication is prevented, while excess nutrients, oversaturation and a possible ensuing degradation is avoided at the same time.
  • The 6th Environmental Action Programme (Decision No 1600/2002/EC) encourages the full implementation of WFD, in order to achieve levels of water quality that do not give rise to unacceptable impacts on, and risks to, human health and the environment.
  • Rural Development Programme (RDP): Various agri-environment measures have been established throughout the European Union directly or indirectly addressing diffuse contamination by phosphorus. Some of these measures are directed at mitigating soil erosion such as crop rotations, mulch seeding retaining stubble after harvest and ploughing restrictions. Other measures tackle the problem of excess nutrients through reduced fertiliser use. All measures that impact soil erosion and nutrient balances ultimately result in a reduction of diffuse contamination by phosphates from agricultural land. Phosphorus balances are required for the RDP 2007-2013 (Council Regulation No 1698/2005) as part of the EU’s Common monitoring and evaluation framework to assess the impact of RDP.

See also

Further Eurostat information

Publications

Database

Farm Management (aei_fm)
Consumption estimate of manufactured fertilizers (source: Fertilizers Europe) (aei_fm_manfert)
Pressures and risks (aei_pr)
Gross Nutrient Balance (aei_pr_gnb)
Structure of agricultural holdings (ef)
Structure of agricultural holdings: historical data (1990-2007) (ef_h)
Land Use (ef_lu)
Land use overview (ef_lu_ov)
Farmland: Number of farms and areas by size of farm (UAA) and region (ef_lu_ovcropaa)
Livestock (ef_ls)
Livestock overview (ef_ls_ov)
Livestock: Number of farms and heads by size of farm (UAA) and region (ef_ls_ovaareg)
Agricultural products (apro)
Crops products (apro_cp)
Crops products: areas and productions (apro_cpp)
Crops products (excluding fruits and vegetables) (annual data) (apro_cpp_crop)
Land use - 1 000 ha (annual data) (apro_cpp_luse)
Animal production (apro_mt)
Livestock (apro_mt_ls)
Cattle population (annual data) (apro_mt_lscatl)
Goats population (annual data) (apro_mt_lsgoat)
Sheep population (annual data) (apro_mt_lssheep)
Pig population (annual data) (apro_mt_lspig)

Dedicated section

Agri-environmental Indicators

Methodology / Metadata

Source data for tables, figures and maps on this page (MS Excel)

Excel.jpg Download Gross Phosphorus Balances Excel file

Other information

External links


Notes

  1. Phosphorus in agriculture: global resources, trends and developments : report to the Steering Committee Technology Assessment of the Ministery of Agriculture, Nature and Food Quality, The Netherlands Smit, A.L. ; Bindraban, P.S. ; Schröder, J.J. ; Conijn, J.G. ; Meer, H.G. van der Wageningen : Plant Research International 2009 http://www.stuurgroepta.nl/rapporten/phosphorusinagriculture.pdf
  2. Phosphate – from surplus to shortage. Policy memorandum of the Steering Committee for Technology Assessment of the Ministry of Agriculture, Nature and Food Quality H.A. Udo de Haes, J.L.A. Jansen, W.J. van der Weijden and A.L. Smit, Utrecht, September 2009
  3. Bomans E., Fransen K., Gobin A., Mertens J., Michiels P.,Vandendriessche H., Vogels N. Addressing phosphorus related problems in farm practice. Final report to the European Commission. Soil Service of Belgium
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