Pollution solutions benefit all

6 July 2001

Pollution solutions benefit all

PRODUCERS should not be put off by increasing pressure to cut environmental pollution, as solutions often save costs, instead of being an extra burden.

Speaking at its Press briefing, Frank Wright technical director, John Allen, said the inclusion of the Environment Protection Group within the Department of Environment, Food and Rural Affairs confirmed that agriculture must stay in touch with environmental needs.

One issue highlighted by Catherine Watson, Queens University of Belfast, is that only 7% of nitrogen is converted into animal products, much lower than 60% for crops. "More importantly, this efficiency falls with increasing fertiliser use because of a greater nitrogen surplus," she said.

"In Northern Ireland, the annual surplus of nitrogen is about 120,000t a year which equates to 130kg/ha of wasted fertiliser nitrogen. There is much scope for reducing this surplus and lowering fertiliser costs."

Urine and dung patches are also a problem because nitrogen is unevenly distributed on grassland. "Nitrogen loading in a urine patch is equivalent to applying 1000kg/ha nitrogen fertiliser," said Dr Watson.

"Phosphorus surpluses are also widespread, with more than half of soils in Northern Ireland containing excess phosphorous, compared with only 4% in the 1940s. Phosphorous enrichment of fresh water is the main cause of toxic algal blooms."

Algal blooms were an increasing problem in Lough Neagh, but water phosphorous had started to fall back over the past two years, she said. That could be the early benefits of improved fertiliser practices on farms.

"There is much scope for reducing nitrogen and phosphorous pollution by matching application of fertiliser and manure to crop needs. It is essential to test soil annually for nitrogen and phosphorus status and allow for the supply of these nutrients in slurry and manure when calculating fertiliser rates."

Dr Watson also encouraged fertiliser manufacturers to change their products to reflect changes in soil status over the past few years. "Fertiliser phosphorus content should be reduced and potassium and sulphur increased.

"To ensure success in reducing pollution from agriculture, collaboration between producers, researchers, fertiliser companies and feed compounders is essential. It will not work unless all are committed to reducing nutrient losses," she said.

POLLUTION

&#8226 Large nitrogen surpluses.

&#8226 Analyse soil and slurry.

&#8226 Consider fertiliser composition.