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Mineral accounting: the way to combat eutrophication and to achieve the drinking water objective
ENVIRONMENTAL POLLUTION Environmental Pollution 102, Sl (1998) 705-709
Mineral accounting: the way to combat eutrophication achieve the drinking water objective
and to
H.M.P. van den Brandt, H.P. Smit* Ministry of Agrkulture, Nature Management and Fisheries, Den Haag, The Netherlands
Received 27 March 1998; accepted 12 September 1998
Abstract In 1998 the Netherlands government introduced a new manure policy in order to combat pollution of the environment by an excess supply of nutrients in agriculture. This policy is based on a mineral accounting system (MINAS) at the farm level and is focused more on nitrogen than in the past. MINAS came into force by an alteration of the law on fertilisers (Meststoffenwet). In MINAS chemical nitrogen fertilisers are included, because the use of these fertilisers contributes in the same order of magnitude to nitrogen surpluses as the application of animal manure. The new policy aims to alleviate the nitrogen problems caused in the period 199&2008/2010. By implementing MINAS surface waters will eventually be protected against eutrophication and the quality of groundwater used for drinking water will improve. Farms record all nutrient inputs and outputs accurately and report their farm surplus. A surplus exceeding the levy-free surplus is subject to a charge. The levy-free surplus will diminish in the period 1998-2008/2010. MINAS is only practicable if a balance exists between production of and demand for animal manure. Therefore the Dutch government has decided on a 20% reduction in the number of pigs in the short term. Keywora’s:
Mineral accounting; mineral surplus; levy; eutrophication;
Introduction
The Dutch manure policy dates back to the mid1980s. It was introduced by the government in order to reduce the effects of manure surpluses on the quality of air, soil and water, resulting for example in eutrophication and acidification. This article concentrates on eutrophication and groundwater quality. Eutrophication occurs when there is a surplus of nitrogen and phosphates in the soil or water, which threatens their quality. Natural ecosystems are affected through the deposition of ammonia, enriching the soil with nitrogen. For example, heathlands are overtaken by grass, whilst in forest areas brambles (Rubus sp.) proliferate. Leaching of nitrates may increase concentrations in * Corresponding author. Tel. +-31-70-378 4389; fax: +31-70-378 6161; e-mail: [email protected]
groundwater quality
groundwater. The Dutch quality limit established for groundwater is 50 mg per litre (VROM, 1998) and agrees with the standard for drinking water of the EU-Drinking Water Directive (European Commission, 1980) and a guideline in the EU-Nitrate Directive (European Commission, 1991) to indicate vulnerable zones. Monitoring shows that the 50 mg quality standard is frequently exceeded, sometimes even by a factor of two or more, particularly in the shallow groundwater layers under sandy soils. In deeper drinking water wells the concentration is normally lower than the target value of 25 mg per litre (VROM, 1991; V&W, 1994), although a progressive increase is clearly visible. Eutrophication of surface waters is caused by the discharge of wastewater from industry and diffuse leaching of minerals from agriculture. This leads to excessive growth of algae and eventually to an overabundance of blue-green algae, which clouds the water, unbalancing water ecosystems: predatory fish, such as pike, dis-
706
H.M.P. van den Brandt, H.P. Smit /Environmental Pollution 102, Sl (1998) 705-709
appear, and bream, which does not need fresh water, can become the dominant species. In ditches eutrophication leads to an increase of duckweed. Phosphate and nitrate enrichment also have a negative effect on the quality of bathing water. The government regards eutrophication as a serious issue, which can be illustrated by the Dutch policy regarding treatment facilities for sewage water. Many such installations in the Netherlands have taken technical measures to remove nitrogen and phosphate from sewage waters. Now water quality is improving, which enables ecosystems to recover. Policy up to 1998 Agriculture adds considerably to the emission of nutrients. Over 60% of nitrogen in surface waters, for example, originates from agriculture. The relative contribution of agriculture to the eutrophication of surface waters caused by phosphates is about 40%. Dutch agriculture is intensive. Hence, the area of agriculture is limited: 2 million hectares, of which 1 million is grassland. Despite the limited area the annual production is valued at $37 billion, the larger part of which is exported. After the United States ($ 66 billion) and France ($ 40 billion), the Netherlands rank third when it comes to the export of agricultural products (FAO, 1998). The cattle population amounts to 4.5 million, of which 1.5 million is dairy cattle. Furthermore, there are about 85 million laying hens and broilers. The number of pigs was around 14.5 million until 1997, but due to swine fever in 1997 the number of pigs has decreased by approximately 20%. Pig and poultry farms in particular are faced with excess manure at production level. In contrast to most dairy farms, most of these are non-land using systems, so they cannot spread their manure on their own land. The phosphate surplus on farms with dairy cattle and beef cattle is 4.5 million kg (17 million kg nitrogen) totally, whilst the total phosphate surplus on pig farms is 45 million kg (114 million kg nitrogen) and on poultry farms 28 million kg (42 million kg nitrogen) (LNV, 1998; LEI, 1997). The excess manure from intensive livestock farms must therefore be sold to arable farmers in areas where livestock density is low. From 1987 onwards, the government has followed a policy to reduce gradually the pollution of soil and water by phosphates and nitrogen in order to decrease the problems caused by these nutrients from manure. The government has taken various measures such as: - the amount of animal manure per hectare has been limited to a certain maximum and this threshold has subsequently been lowered considerably; - total livestock numbers have been limited; - between the 1 September and 1 February, periods have been set during which spreading is not allowed.
These are general measures applying to every farmer; the government did not discriminate farmers with relatively good nutrient management from farmers with relatively bad. Furthermore, the government encouraged the export of poultry manure, internal transports of animal manure to areas with relative low livestock densities, and the use of animal feed low in mineral content. Up to 1997 these measures have had the following results: - the flows of nitrogen and phosphate entering the soil have been reduced; - the excretion of phosphate in the pig farming sector has decreased by approximately 30% since 1987 through improved feed; - in recent years, about 30%-40% of poultry manure has been exported abroad; - the distribution of excess manure from pig and poultry farms has improved: 15 million tons of manure is transported annually from areas with high livestock densities to areas with low livestock densities; - the use of chemical nitrogen fertiliser has decreased by approximately 25% from 1985 to 1995. Large-scale manure processing was a spearhead of Dutch manure policy. However, it did not really take off in the Netherlands, due to technical and economic problems in the processing installations. Future policy Although Dutch policy has been reasonably successful so far, further progress is required. The general measures have not been effective enough to achieve the objectives of the manure policy. Secondly, farmers see these measures as too discriminating. Thirdly, the manure policy has been focused so far on the reduction of phosphate in animal manure. The problems caused by nitrogen have not been adequately addressed. The nitrogen burden arises not only from animal manure, but also from nitrogen in chemical fertilisers. The Dutch manure policy for the next 12 years has been re-evaluated and, as of 1 January 1998, there is a new approach: the Mineral Accounting System (MINAS) (Staatsblad, 1997). This new approach focuses on: 1.
The individual farmer; the reasons for this change are: (a) research and experience have shown that measures to limit the leaching of nitrogen and phosphate to the environment can vary from one farm to another. There are no general measures that can be applied to every farm; (b) Farms with high livestock densities are often associated with high mineral surpluses. However, comparative studies of dairy farming on sandy soils (DELAR, 1993) show that intensive livestock farms do not necess-
H.M.P. van den Brandt, H.P. Smit I Environmental Pollution 102, Sl (1998) 705-709
707
arily produce high surpluses, if the nutrient management at farm level is good enough (Fig. 1). The conclusion is that nutrient management is often a more important factor than livestock density (De Vries, experimental farm ‘De Marke’, pers. comm.). 2.
Chemical fertilisers are given proper attention. Nitrogen-related problems are not only caused by animal manure in the Netherlands, but also by chemical nitrogen fertilisers. Until 1998, however, the policy did not cover chemical fertilisers. Therefore the MINAS pays special attention to nitrogen, either in the form of animal manure or in the form of fertilisers.
The new policy aims at solving the eutrophication problem during the period up to 2010 through enforceable and realistic measures. The goal is also to comply with the EU Nitrate Directive. Mineral Accounting System (MINAS) at farm level The Mineral Accounting System is a “farm gate balance approach” (I?ig. 2). From 1998 onwards the system will apply to the most intensive livestock farmers, with a density of more than 2.5 LU per hectare. In 2000 the system will be extended to all livestock farmers and in 2002 to other agricultural holdings, including arable farmers. The reason for starting with intensive units is that these pose the greatest risk to the environment. All nitrogen and phosphate flows must be accurately recorded, on the basis of transaction documents. Flows entering the farm are, for example, fertiliser and animal feed. Examples of flows leaving the farm are animal products (such as live cattle, meat, milk and eggs) and plant products (such as harvested crops). Livestock manure originating from and used on the farm itself does not enter the balance. Animal manure imported from other farms does enter the balance, as does animal manure leaving the farm. The manure entering and leaving must be sampled and analysed for phosphate and nitrogen. Every movement of manure is weighed, in order to register accuratelysthe imports/exports of minerals onto/ off the farm. MINAS is a complex system, because all items of mineral exports and mineral imports on the farm have to be registered. In addition, the system is in principle susceptible to fraud, because it is based on actual contents of phosphate and nitrogen instead of general standards in manure. The goal is to minimise the farm’s surplus to a certaiti level, the levy-free surplus. This level determines the degree of environmental damage. If the mineral surplus exceeds this limit, the farmer has to pay levy over the excess. MINAS is a flexible system. The system gives the farmer the opportunity to meet the environmental objectives with measures which best fit the farmer’s
Fig. 1. Farms with low and high livestock densities and different nitrogen surpluses. 25% of the farms with livestock densities over 3 livestock units per hectare have lower nitrogen surpluses than the average farm with a livestock density of 2 LU/ha. (Source: DELAR, 1993)
Fig. 2. The Mineral Accounting System is a farm gate balance approach. Farmers have to register all imports and exports of nitrogen and phosphate accurately and have to report the farm surpluses.
individual situation. This makes this system more flexible than an approach with a series of general measures to be applied on every farm as required under the policy until 1998. In applying the new approach the nitrate objective for groundwater can be attained for the larger part of the Netherlands. Areas with dry sandy soils are an exception; for these cases additional nitrate policy is being developed. These soils cover approximately 12% of all agricultural land in the Netherlands (Oenema et al, 1997). The levy-free surplus for nitrogen and phosphate will be gradually lowered to a level which will ensure that the
H.M.P. van den Brandt, H.P. Smit / Environmental Pollution 102, SI (1998) 705-709
108
Table 1 Levy-free surpluses per hectare applicable to all farms participating in the Mineral Accounting System (kg/ha) 1998
2ooO
2002
2005
2008/2010
-grassland
300
275
250
200
180
- arable land
175
150
125
110
100
40
35
30
25
20
brium on the internal manure market will fail. The largest quantity of manure to be transported from farms is pig manure. Therefore, the government will reduce the pig herd by 20% by the year 2000.
Nitrogen
Phosphate
Source: LNV (1995).
environmental objectives in the period between 1998 and 2008/2010 are met (Table 1). Levies encourage farmers actually to limit their losses. As the levy-free surpluses are lowered, farmers will have to limit the use of nitrogen and phosphate, and increase nutrient-efficiency. The levy for nitrogen is equivalent to the current costs for fertiliser nitrogen: Dfl 1.50 per kg of pure nitrogen (ca $0.75/kg). This has the effect that a farmer, in order not to exceed the levy-free surplus, will be critical regarding the purchase of fertilisers. The levy for phosphate is determined so as to ensure that a farmer does not apply his phosphate surplus to his own land but transports it to arable farms. The phosphate levy is Dfl 2.50 per kg of phosphate (ca $1.25/kg P,O,) for the first ten kilograms exceeding the levy-free surplus. The levy is DfllO.00 (ca $ 5.OO/kg P,O,) for every next kilogram of phosphate surplus. Payments of individual farmers are expected to be nil to several thousands of guilders. It is not the government’s intention to charge farmers as much as possible. The levies are meant to stimulate a change in farming practices. The levies paid by the farmers are taxes which flow into the public revenues of the state. The expected public revenues from these levy taxes may amount to 16 million guilders yearly (LNV, 1995). The Dutch livestock farmers are pleased that the government has abandoned the general approach, and instead makes farmers individually accountable. However, the farmers are concerned as to whether the government’s targets can be met, in particular those that apply from 2000 onwards. The policy will be evaluated in 2000. On the basis of the surpluses in practice and the results at pilot and model farms it will be decided whether there is sufficient reason to adjust either the loss standards or the policy. Reduction in the number of pigs The Mineral Accounting System is susceptible to fraud and will only function optimally if equilibrium exists between supply and demand on the national manure market. If this market is out of equilibrium, the transport costs will increase and so will the inclination to practise fraud. Without additional measures, equili-
MINAS is the optimal system for the Dutch situation A study carried out by various Dutch environmental and agricultural institutes (Oenema et al., 1997) shows that, when the Mineral Accounting System is fully implemented by the year 2010, the nitrogen surplus on farms may decrease by 50% compared to the year 1986. Nitrogen emission to surface water is expected to decrease by approximately 40%. Average nitrate concentrations in groundwater might decrease by 60%, and the groundwater quality objective of 50 mg nitrate per litre is also attainable with the new policy on manure and ammonia emissions. This study refers to an experimental farm in an area with dry sandy soils “De Marke”. After implementing a registration method of nutrient flows like the MINAS principle at farm level the leaching of nitrogen has dropped drastically. This study has shown that the Mineral Accounting System is a reliable method of achieving the clean drinking water objective (Oenema et al., 1997). The Dutch government considers that, in the Dutch situation, the mineral accounting system is a useful instrument. In order to attain its environmental objectives the government establishes an account with every farmer on their environmental performance. Every farmer, however, is free to decide the best means of reducing his burden on the environment to acceptable levels.
References DELAR, 1993: Accountancy of the Dairy Husbandry. Research Station for Cattle, Sheep and Horses, Lelystad (in Dutch). European Commission, 1980. Council Directive 80/778/EEC of 15 July relating to the quality of water intended for human consumption. Official Journal of the European Commission No L 229.30.8.1980, p. 11. European Commission, 1991. Council Directive 91/676/EEC of 12 December concerning the protection of waters against pollution caused by nitrates from agricultural sources. Official Journal of the European Commission No L 375,30.12.1991. FAO, 1998. FAO Statistical Data. www.fao.org. LEI, 1997. Agriculture, Environment and Economy, edition 1997. F. Brouwer, C.H.G. Daatselaar, J.P.P.J. Welten and J.H.M. Wijnands (Eds.). Agricultural Economics Research Institute (LEI-DLO) Den Haag (in Dutch). LNV, 1995. Policy Document on Minerals and Ammonia. Ministry of Agriculture, Nature Management and Fisheries. Dutch Parliament, assembly 1995-1996,24 445, no. 1. SDU Uitgeverij, Den Haag (in Dutch) LNV, 1998: Facts and Figures 1997/1998. Ministry for Agriculture, Nature Management and Fisheries, The Hague.
H.M.P. van den Brandt, H.P. Smit / Environmental Pollution 102, Sl (1998) 705-709
Oenema, O., Broers, P.C.M., van Eerdt, M.M., Fraters, B., van der Meer, H.G., Roest, C.W.J., Schriider, J.J., Willems, W.J., 1997. The nitrate problem and nitrate policy in the Netherlands. Nota 88, Research Institute for Agrobiology and Soil Fertility (AB-DLO), Haren. Staatsblad, 1997: Act of May 2, 1997, concerning emendation of the Fertiliser Act. Royal Statute-book of the Netherlands 1997/360 (in Dutch). VROM, 1991. Policy Document Environmental Quality Objectives
709
Soil and Water. Ministry of Housing, Spatial Planning and Environment. Dutch Parliament, assembly 1990-1991, 21 990, nr 1. SDU Uitgeverij, 1991 (in Dutch). VROM, 1998. National Environment Policy Plan 3. Ministry of Housing, Spatial Planning and Environment Den Haag (in Dutch). V&W, 1994. Evaluation Document on Water Policy. Ministry of Transport and Public Works and Water Management. Dutch parliament, assembly 1993-1994,212.50, nos. 27-28. SDU Uitgeverij, Den Haag (in Dutch).
Mineral accounting: the way to combat eutrophication achieve the drinking water objective
and to
H.M.P. van den Brandt, H.P. Smit* Ministry of Agrkulture, Nature Management and Fisheries, Den Haag, The Netherlands
Received 27 March 1998; accepted 12 September 1998
Abstract In 1998 the Netherlands government introduced a new manure policy in order to combat pollution of the environment by an excess supply of nutrients in agriculture. This policy is based on a mineral accounting system (MINAS) at the farm level and is focused more on nitrogen than in the past. MINAS came into force by an alteration of the law on fertilisers (Meststoffenwet). In MINAS chemical nitrogen fertilisers are included, because the use of these fertilisers contributes in the same order of magnitude to nitrogen surpluses as the application of animal manure. The new policy aims to alleviate the nitrogen problems caused in the period 199&2008/2010. By implementing MINAS surface waters will eventually be protected against eutrophication and the quality of groundwater used for drinking water will improve. Farms record all nutrient inputs and outputs accurately and report their farm surplus. A surplus exceeding the levy-free surplus is subject to a charge. The levy-free surplus will diminish in the period 1998-2008/2010. MINAS is only practicable if a balance exists between production of and demand for animal manure. Therefore the Dutch government has decided on a 20% reduction in the number of pigs in the short term. Keywora’s:
Mineral accounting; mineral surplus; levy; eutrophication;
Introduction
The Dutch manure policy dates back to the mid1980s. It was introduced by the government in order to reduce the effects of manure surpluses on the quality of air, soil and water, resulting for example in eutrophication and acidification. This article concentrates on eutrophication and groundwater quality. Eutrophication occurs when there is a surplus of nitrogen and phosphates in the soil or water, which threatens their quality. Natural ecosystems are affected through the deposition of ammonia, enriching the soil with nitrogen. For example, heathlands are overtaken by grass, whilst in forest areas brambles (Rubus sp.) proliferate. Leaching of nitrates may increase concentrations in * Corresponding author. Tel. +-31-70-378 4389; fax: +31-70-378 6161; e-mail: [email protected]
groundwater quality
groundwater. The Dutch quality limit established for groundwater is 50 mg per litre (VROM, 1998) and agrees with the standard for drinking water of the EU-Drinking Water Directive (European Commission, 1980) and a guideline in the EU-Nitrate Directive (European Commission, 1991) to indicate vulnerable zones. Monitoring shows that the 50 mg quality standard is frequently exceeded, sometimes even by a factor of two or more, particularly in the shallow groundwater layers under sandy soils. In deeper drinking water wells the concentration is normally lower than the target value of 25 mg per litre (VROM, 1991; V&W, 1994), although a progressive increase is clearly visible. Eutrophication of surface waters is caused by the discharge of wastewater from industry and diffuse leaching of minerals from agriculture. This leads to excessive growth of algae and eventually to an overabundance of blue-green algae, which clouds the water, unbalancing water ecosystems: predatory fish, such as pike, dis-
706
H.M.P. van den Brandt, H.P. Smit /Environmental Pollution 102, Sl (1998) 705-709
appear, and bream, which does not need fresh water, can become the dominant species. In ditches eutrophication leads to an increase of duckweed. Phosphate and nitrate enrichment also have a negative effect on the quality of bathing water. The government regards eutrophication as a serious issue, which can be illustrated by the Dutch policy regarding treatment facilities for sewage water. Many such installations in the Netherlands have taken technical measures to remove nitrogen and phosphate from sewage waters. Now water quality is improving, which enables ecosystems to recover. Policy up to 1998 Agriculture adds considerably to the emission of nutrients. Over 60% of nitrogen in surface waters, for example, originates from agriculture. The relative contribution of agriculture to the eutrophication of surface waters caused by phosphates is about 40%. Dutch agriculture is intensive. Hence, the area of agriculture is limited: 2 million hectares, of which 1 million is grassland. Despite the limited area the annual production is valued at $37 billion, the larger part of which is exported. After the United States ($ 66 billion) and France ($ 40 billion), the Netherlands rank third when it comes to the export of agricultural products (FAO, 1998). The cattle population amounts to 4.5 million, of which 1.5 million is dairy cattle. Furthermore, there are about 85 million laying hens and broilers. The number of pigs was around 14.5 million until 1997, but due to swine fever in 1997 the number of pigs has decreased by approximately 20%. Pig and poultry farms in particular are faced with excess manure at production level. In contrast to most dairy farms, most of these are non-land using systems, so they cannot spread their manure on their own land. The phosphate surplus on farms with dairy cattle and beef cattle is 4.5 million kg (17 million kg nitrogen) totally, whilst the total phosphate surplus on pig farms is 45 million kg (114 million kg nitrogen) and on poultry farms 28 million kg (42 million kg nitrogen) (LNV, 1998; LEI, 1997). The excess manure from intensive livestock farms must therefore be sold to arable farmers in areas where livestock density is low. From 1987 onwards, the government has followed a policy to reduce gradually the pollution of soil and water by phosphates and nitrogen in order to decrease the problems caused by these nutrients from manure. The government has taken various measures such as: - the amount of animal manure per hectare has been limited to a certain maximum and this threshold has subsequently been lowered considerably; - total livestock numbers have been limited; - between the 1 September and 1 February, periods have been set during which spreading is not allowed.
These are general measures applying to every farmer; the government did not discriminate farmers with relatively good nutrient management from farmers with relatively bad. Furthermore, the government encouraged the export of poultry manure, internal transports of animal manure to areas with relative low livestock densities, and the use of animal feed low in mineral content. Up to 1997 these measures have had the following results: - the flows of nitrogen and phosphate entering the soil have been reduced; - the excretion of phosphate in the pig farming sector has decreased by approximately 30% since 1987 through improved feed; - in recent years, about 30%-40% of poultry manure has been exported abroad; - the distribution of excess manure from pig and poultry farms has improved: 15 million tons of manure is transported annually from areas with high livestock densities to areas with low livestock densities; - the use of chemical nitrogen fertiliser has decreased by approximately 25% from 1985 to 1995. Large-scale manure processing was a spearhead of Dutch manure policy. However, it did not really take off in the Netherlands, due to technical and economic problems in the processing installations. Future policy Although Dutch policy has been reasonably successful so far, further progress is required. The general measures have not been effective enough to achieve the objectives of the manure policy. Secondly, farmers see these measures as too discriminating. Thirdly, the manure policy has been focused so far on the reduction of phosphate in animal manure. The problems caused by nitrogen have not been adequately addressed. The nitrogen burden arises not only from animal manure, but also from nitrogen in chemical fertilisers. The Dutch manure policy for the next 12 years has been re-evaluated and, as of 1 January 1998, there is a new approach: the Mineral Accounting System (MINAS) (Staatsblad, 1997). This new approach focuses on: 1.
The individual farmer; the reasons for this change are: (a) research and experience have shown that measures to limit the leaching of nitrogen and phosphate to the environment can vary from one farm to another. There are no general measures that can be applied to every farm; (b) Farms with high livestock densities are often associated with high mineral surpluses. However, comparative studies of dairy farming on sandy soils (DELAR, 1993) show that intensive livestock farms do not necess-
H.M.P. van den Brandt, H.P. Smit I Environmental Pollution 102, Sl (1998) 705-709
707
arily produce high surpluses, if the nutrient management at farm level is good enough (Fig. 1). The conclusion is that nutrient management is often a more important factor than livestock density (De Vries, experimental farm ‘De Marke’, pers. comm.). 2.
Chemical fertilisers are given proper attention. Nitrogen-related problems are not only caused by animal manure in the Netherlands, but also by chemical nitrogen fertilisers. Until 1998, however, the policy did not cover chemical fertilisers. Therefore the MINAS pays special attention to nitrogen, either in the form of animal manure or in the form of fertilisers.
The new policy aims at solving the eutrophication problem during the period up to 2010 through enforceable and realistic measures. The goal is also to comply with the EU Nitrate Directive. Mineral Accounting System (MINAS) at farm level The Mineral Accounting System is a “farm gate balance approach” (I?ig. 2). From 1998 onwards the system will apply to the most intensive livestock farmers, with a density of more than 2.5 LU per hectare. In 2000 the system will be extended to all livestock farmers and in 2002 to other agricultural holdings, including arable farmers. The reason for starting with intensive units is that these pose the greatest risk to the environment. All nitrogen and phosphate flows must be accurately recorded, on the basis of transaction documents. Flows entering the farm are, for example, fertiliser and animal feed. Examples of flows leaving the farm are animal products (such as live cattle, meat, milk and eggs) and plant products (such as harvested crops). Livestock manure originating from and used on the farm itself does not enter the balance. Animal manure imported from other farms does enter the balance, as does animal manure leaving the farm. The manure entering and leaving must be sampled and analysed for phosphate and nitrogen. Every movement of manure is weighed, in order to register accuratelysthe imports/exports of minerals onto/ off the farm. MINAS is a complex system, because all items of mineral exports and mineral imports on the farm have to be registered. In addition, the system is in principle susceptible to fraud, because it is based on actual contents of phosphate and nitrogen instead of general standards in manure. The goal is to minimise the farm’s surplus to a certaiti level, the levy-free surplus. This level determines the degree of environmental damage. If the mineral surplus exceeds this limit, the farmer has to pay levy over the excess. MINAS is a flexible system. The system gives the farmer the opportunity to meet the environmental objectives with measures which best fit the farmer’s
Fig. 1. Farms with low and high livestock densities and different nitrogen surpluses. 25% of the farms with livestock densities over 3 livestock units per hectare have lower nitrogen surpluses than the average farm with a livestock density of 2 LU/ha. (Source: DELAR, 1993)
Fig. 2. The Mineral Accounting System is a farm gate balance approach. Farmers have to register all imports and exports of nitrogen and phosphate accurately and have to report the farm surpluses.
individual situation. This makes this system more flexible than an approach with a series of general measures to be applied on every farm as required under the policy until 1998. In applying the new approach the nitrate objective for groundwater can be attained for the larger part of the Netherlands. Areas with dry sandy soils are an exception; for these cases additional nitrate policy is being developed. These soils cover approximately 12% of all agricultural land in the Netherlands (Oenema et al, 1997). The levy-free surplus for nitrogen and phosphate will be gradually lowered to a level which will ensure that the
H.M.P. van den Brandt, H.P. Smit / Environmental Pollution 102, SI (1998) 705-709
108
Table 1 Levy-free surpluses per hectare applicable to all farms participating in the Mineral Accounting System (kg/ha) 1998
2ooO
2002
2005
2008/2010
-grassland
300
275
250
200
180
- arable land
175
150
125
110
100
40
35
30
25
20
brium on the internal manure market will fail. The largest quantity of manure to be transported from farms is pig manure. Therefore, the government will reduce the pig herd by 20% by the year 2000.
Nitrogen
Phosphate
Source: LNV (1995).
environmental objectives in the period between 1998 and 2008/2010 are met (Table 1). Levies encourage farmers actually to limit their losses. As the levy-free surpluses are lowered, farmers will have to limit the use of nitrogen and phosphate, and increase nutrient-efficiency. The levy for nitrogen is equivalent to the current costs for fertiliser nitrogen: Dfl 1.50 per kg of pure nitrogen (ca $0.75/kg). This has the effect that a farmer, in order not to exceed the levy-free surplus, will be critical regarding the purchase of fertilisers. The levy for phosphate is determined so as to ensure that a farmer does not apply his phosphate surplus to his own land but transports it to arable farms. The phosphate levy is Dfl 2.50 per kg of phosphate (ca $1.25/kg P,O,) for the first ten kilograms exceeding the levy-free surplus. The levy is DfllO.00 (ca $ 5.OO/kg P,O,) for every next kilogram of phosphate surplus. Payments of individual farmers are expected to be nil to several thousands of guilders. It is not the government’s intention to charge farmers as much as possible. The levies are meant to stimulate a change in farming practices. The levies paid by the farmers are taxes which flow into the public revenues of the state. The expected public revenues from these levy taxes may amount to 16 million guilders yearly (LNV, 1995). The Dutch livestock farmers are pleased that the government has abandoned the general approach, and instead makes farmers individually accountable. However, the farmers are concerned as to whether the government’s targets can be met, in particular those that apply from 2000 onwards. The policy will be evaluated in 2000. On the basis of the surpluses in practice and the results at pilot and model farms it will be decided whether there is sufficient reason to adjust either the loss standards or the policy. Reduction in the number of pigs The Mineral Accounting System is susceptible to fraud and will only function optimally if equilibrium exists between supply and demand on the national manure market. If this market is out of equilibrium, the transport costs will increase and so will the inclination to practise fraud. Without additional measures, equili-
MINAS is the optimal system for the Dutch situation A study carried out by various Dutch environmental and agricultural institutes (Oenema et al., 1997) shows that, when the Mineral Accounting System is fully implemented by the year 2010, the nitrogen surplus on farms may decrease by 50% compared to the year 1986. Nitrogen emission to surface water is expected to decrease by approximately 40%. Average nitrate concentrations in groundwater might decrease by 60%, and the groundwater quality objective of 50 mg nitrate per litre is also attainable with the new policy on manure and ammonia emissions. This study refers to an experimental farm in an area with dry sandy soils “De Marke”. After implementing a registration method of nutrient flows like the MINAS principle at farm level the leaching of nitrogen has dropped drastically. This study has shown that the Mineral Accounting System is a reliable method of achieving the clean drinking water objective (Oenema et al., 1997). The Dutch government considers that, in the Dutch situation, the mineral accounting system is a useful instrument. In order to attain its environmental objectives the government establishes an account with every farmer on their environmental performance. Every farmer, however, is free to decide the best means of reducing his burden on the environment to acceptable levels.
References DELAR, 1993: Accountancy of the Dairy Husbandry. Research Station for Cattle, Sheep and Horses, Lelystad (in Dutch). European Commission, 1980. Council Directive 80/778/EEC of 15 July relating to the quality of water intended for human consumption. Official Journal of the European Commission No L 229.30.8.1980, p. 11. European Commission, 1991. Council Directive 91/676/EEC of 12 December concerning the protection of waters against pollution caused by nitrates from agricultural sources. Official Journal of the European Commission No L 375,30.12.1991. FAO, 1998. FAO Statistical Data. www.fao.org. LEI, 1997. Agriculture, Environment and Economy, edition 1997. F. Brouwer, C.H.G. Daatselaar, J.P.P.J. Welten and J.H.M. Wijnands (Eds.). Agricultural Economics Research Institute (LEI-DLO) Den Haag (in Dutch). LNV, 1995. Policy Document on Minerals and Ammonia. Ministry of Agriculture, Nature Management and Fisheries. Dutch Parliament, assembly 1995-1996,24 445, no. 1. SDU Uitgeverij, Den Haag (in Dutch) LNV, 1998: Facts and Figures 1997/1998. Ministry for Agriculture, Nature Management and Fisheries, The Hague.
H.M.P. van den Brandt, H.P. Smit / Environmental Pollution 102, Sl (1998) 705-709
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