Dáil Éireann Debate, Wednesday - 18 April 2012
1144 Deputy Patrick Nulty asked the Minister for Agriculture, Food and the Marine if his attention has been drawn to international concerns regarding the future scarcity of phosphorus; if steps are being considered to pre-empt the possible shortage, including the recovery of phosphate from wastewater systems; and if he will make a statement on the matter. [19193/12]
View answerPhosphorus is an essential nutrient for agriculture, necessary for both production of herbage, such as crops and grassland but also as an important mineral for animal production. It is also an expensive nutrient for Irish agriculture and if present in excess quantities can result in diminished water qualities. It is indeed correct to state that it is a mineral of finite supply.
A number of estimates have been made as to the longevity of this resource, but these estimates vary significantly. One such estimate indicates that the viable reserves of phosphate rock could last from as low as 48 years to as high as 235 years depending on usage patterns.
The European Communities (Good Agricultural Practice for the protection of Waters) Regulations 2010, commonly described as the Nitrates Regulations, which is administered by both the Department of Environment and Local Government and my own Department sets out the appropriate limits for application of phosphorus on crops and grassland. This, while aimed principally at preventing negative impacts on water quality arising from excess application of phosphorus to land, also ensures that this scare resource is applied at appropriate levels on Irish farms.
In addition, both my own Department and Teagasc provides guidance on the most efficient use of organic manures such as slurry (including from the Pig and Poultry sector) which are a very good source of phosphorus ensuring that effective recycling of this nutrient takes place on farms. The overall usage of fertiliser phosphorus in Agriculture in Ireland has decreased from 62,000 tons in 1995 to 29,000 tons in 2010.
In relation to the recovery of phosphate from waste water treatment systems, I am advised that it is both difficult and expensive to separate out phosphorus on its own from waste water systems. However as it tends to be bound up in sewage sludge, the recycling of treated sewage sludge (biosolids) to agriculture in accordance with the Waste Management (Use of Sewage Sludge in Agriculture) Regulations, is, in effect, the recycling of phosphorus (as well as organic material) from wastewater treatment to agriculture.
