Features

Nitrates - Are You Vulnerable?

Paul Bell looks at the latest environmental legislation.

Ireland is coming under increasing pressure from the EU Commission to get its act together with regard to the implementation of a number of environment and waste management Directives. The latest "hot potato" to land in the governments' lap is the implementation of the Nitrates Directive. This particular Directive is likely to impose changes on the activities of many farmers.

What exactly is the "Nitrates Directive"?

The Nitrates Directive came into force in December 1991 and is concerned with the protection of waters against pollution caused by nitrates from agricultural sources. It has two primary objectives, namely

1. to reduce water pollution caused or induced by nitrates from agricultural sources, and
2. to prevent further such pollution.

Why nitrates?

High nitrate levels in drinking waters are considered to be a hazard to both human and animal health. They are associated with some forms of cancers, such as those of the stomach and intestines. They may also cause "blue baby" syndrome in babies and young infants due to interference with the infants' ability to carry oxygen in the blood.

Excessive nitrate levels in surface waters will also encourage eutrophication, i.e. the proliferation of green vegetative mass and algal blooms. This plant material uses up all the available oxygen in the water, and aquatic life forms which require oxygen (e.g. fish) are forced to leave, resulting in a "dead" river or stream.

The Directive has been criticised for dealing with nitrates only and not covering all forms of pollution caused by agricultural activities.

How do nitrates from agriculture pollute waters?

The three principal sources of nitrates from agricultural activities are:

1. Animal manures and crop wastes;
2. Chemical fertilisers; and
3. Denitrification of ploughed/arable lands.

Animal and crop wastes (such as silage effluent) contain significant amounts of nitrogen, and the inadequate storage and/or management of these materials leads to nitrate losses to waters. High animal stocking rates increase the manure loading on land and can result in nitrates in excess of the grass growth requirements being washed out of the soil into water bodies. Likewise with chemical fertilisers, the excessive use or poor timing of application of which can lead to nitrogen being washed into the water bodies.

Ploughing grassland for tillage crops increases the amount of nitrogen released from the soil and if this is not immediately utilised by crop plants it is vulnerable to being washed out of the soil layers and into field drains and ultimately the general water system. A certain amount of nitrogen is released each year in ploughed land. Also leaving the soil bare for long periods will increase the risk of nitrogen washing into water bodies

How do we know if nitrate pollution comes from agriculture?

Of course agriculture is not the sole cause of nitrate pollution. Industrial activities, domestic and municipal sewage treatment facilities are also significant sources. It is impossible to tell if a particular molecule of nitrate is from any particular source, agricultural or otherwise. However in areas where the water nitrate levels are high and where there is significant agricultural activity being carried out (i.e. intensive fertiliser use, high animal stocking densities, tillage farming) it is deemed that agriculture is contributing to this pollution and therefore some element of control is required.

What is Ireland required to do under this the Directive?

The key tasks required by the Irish authorities are as follows:

1. To identify all waters affected (or likely to be) by pollution with nitrates from agricultural sources. In the case of drinking water supplies and groundwaters (i.e. bodies of water that are accessible only by springs, wells or bore holes) water is considered "polluted" if the nitrate levels exceed 50 mg/l (or ppm - parts per million) or are likely to do so in the near future. Surface waters are considered polluted if they are found to be eutrophic or likely to become eutrophic in the foreseeable future;
2. To designate as "Vulnerable Zones" all lands which drain into polluted waters as identified above in (i);
3. To establish a Code of Good Agricultural Practice to protect waters from agricultural pollution;
4. To establish Action Programmes in the Vulnerable Zones in order to reduce agricultural pollution, and finally;
5. To monitor the nitrate levels in the water and evaluate the effectiveness of the pollution control measures.

What has Ireland done so far?

The Code of Good Agricultural Practice was established and published in 1996 by the Departments of the Environment and Agriculture (copies should be available from your local Department office). It is due to be further revised in the near future. Under the Directive this Code is applicable on a voluntary basis countrywide, not just in Vulnerable Zones. However in vulnerable zones part or all of the requirements of the Code will be legally binding on farmers. Note that this code should not be confused with the recently introduced " Code of Good Farming Practice" , which aims to establish a minimum set of standards in all aspects of farming practice.

he designation of vulnerable zones is the task that the government is currently under pressure to finalise. The debate is between designating the entire country as a vulnerable zone or just those areas where nitrate levels are highest

The implementation of Action Programmes is dependant on the designation of vulnerable zones, and so has yet to happen.

What is involved in an action programme?

An Action programme consists of a series of legally binding measures which are aimed at reducing pollution and which farmers are required to adhere to. Action Programmes can be specific for different parts of the country, but all such programmes will specify the following:

1. when the land application of certain types of materials such as slurry and manures will be prohibited;
2. the minimum storage capacity required for the stock housed on each farm;
3. the maximum permitted chemical fertiliser rates per hectare.;
4. the maximum levels of animal manures per hectare;

In addition to these, additional measures may be implemented if they are considered necessary to reduce pollution.

The Directive allows for a maximum of 170kgN/ha from animal manures. This is the equivalent of a stocking rate of two cows per ha. This limit may be increased to 210kgN/ha for the first four years of an action programme in order to give farmers some time to adjust if stock numbers need to be reduced. A higher level may be permitted during and after the first four years of an action programme if the Member State can argue a justifiable case for doing so. Any such argument will need to establish that there is a particularly high need for nitrogen. Typical reasons which may permit a higher level would be a long growing season, the growing of crops with a high nitrogen uptake, soils which have an unusually high capacity to tie up nitrogen (and then make it unavailable to the crop),or the incidence of high levels of rain in the vulnerable zone. In each case, the Member State must convince the Commission that in raising the permissible limits it will not reduce the effectiveness of the programme to meet the objectives of the Directive.

The measures are aimed at providing crops (including grass) with the nitrogen they need and no more. The provision of excessive nutrients which are not utilised by the crop increases the risk of pollution.

The farming industry is seeking to have individual areas of land designated as vulnerable zones rather than the whole country. It is in the vulnerable zones that the action programme measures are legally binding. It is the details of the action programme(s) that will be of most concern to farmers, particularly those farmers who are too intensive to join REPS. There will almost certainly be a requirement for the building of new slurry and manure storage facilities, and there will be the question of having to reduce stock numbers in some polluted zones. The limits on fertiliser use will also cause concern.

REPS farmers will already be meeting many of the above mentioned requirements, but there is the question of REPS payments being reduced, as under EU regulations farmers cannot be compensated for carrying out activities which are required by law.

Organic farmers should have little to fear from the Nitrates Directive, as the intensity of their activities is well within the permissible limits. Perhaps there may be some time restrictions when farmyard manure can be applied to the land, but this is not likely to cause any significant difficulties.

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