Code of Practice

Code of Good Practice for the Environment and Quality Food Production.

Soil is the medium for plant growth. For sustainable plant and animal production this medium must be supplied with adequate major and minor nutrients that are essential for plant and animal growth. To support plant and animal production soil nutrient levels must be maintained. Assuming soil pH is satisfactory the common limiting major nutrients are Nitrogen (N); Phosphorus (P); Potassium (K) and sometimes Sulphur (S).

All of these nutrients are involved in key processes within the plant and a deficiency of any one will limit growth, whether it be grass for animal consumption or root and cereal crops for both human and animal consumption.

World population today stands at 5.8 billion and is expected to increase to 8.0 billion by 2020. Cereals are the worlds most important stable nutrient source and to meet future demand cereal production will need to double by the year 2020. Production of other foodstuffs will also have to increase significantly.

Fertiliser, both organic and inorganic, will have to play a vital role if the food production necessary to support the increased population is to be provided.

Efficient recycling of organic manure will provide some of the nutrients necessary but modern crop production will need additional nutrients in the form of inorganic fertilisers. Such nutrients are not artificial, i.e. the nutrients in inorganic fertilisers are natural products and simply supply the shortfall necessary for sustainable crop production.

Nitrogen, Phosphorus and Potassium are naturally occurring elements, which are processed into forms which are readily available for crop growth.

In conclusion, application of inorganic fertiliser is simply the addition of nutrients to the soil nutrient pool, necessary for crop production. It is the misuse of fertiliser or the use of them at the wrong rates and times that lead to environmental damage. The purpose of this section on our website is to outline a code of practice for optimum production without damaging the environment.


This Code of Good Practice has been prepared to maintain optimum production of quality food while at the same time minimising nutrient loss through leaching, runoff or losses to air and thereby prevent any avoidable rise in nitrate and phosphate levels in water.


There are 2 reasons for so doing:

1. Plant Nutrients are valuable

  • 1 tonne of nutrient N costs over 500
  • 1 tonne of nutrient P costs over 1000
  • 1 tonne of nutrient K costs over 400

2. Our Waterways must be protected from nutrient enrichment.

The EC Water Quality Directive requires that drinking water must not contain more than 50 mg/l. of nitrate (11.3 mg/l. expressed as N) and establishes a guideline level of 25 mg/l. of nitrate.

Phosphorus and nitrogen in water may give rise to eutrophication. Nutrient enrichment of the water leads to an overgrowth of algae and aquatic plants which in turn causes depletion of the oxygen in the water, leaving it unable to sustain other forms of life.

If animal manure finds it way into water it increases B.O.D. levels and depletes oxygen supply. Resultant harmful bacterial contamination of the water is a health hazard. Nitrate and phosphates are released, increasing vegetative growth and leading to further eutrophication.

The Favourable Position in Ireland

There are water quality problems in several parts of the European Community. Overall in Ireland the quality of our water is good. It is important that we now redouble our efforts to ensure that our existing high water quality is preserved while improving the quality of our polluted waters.

Soil Nutrient Programme

When devising a fertiliser programme the soil fertility status must be known on foot of regular soil testing. The amounts applied can then be determined to ensure optimum yields without causing environmental damage. There must be full recognition of all sources of nutrients, both organic and inorganic. Regular soil testing is very important to help maintain a balance of nutrients in the soil.