Farming: Union defends use of nitrogen in high-octane climate change debate

NFU Scotland yesterday reacted robustly to claims farming was one of the main contributors to nitrogen pollution in the world.

The union pointed out that nitrogen fertiliser was fundamental to food production and that its responsible and efficient use on farm could benefit both the environment and the farmer's bottom line.

Speaking from the Nitrogen and Global Change Conference in Edinburgh, union vice- president John Picken said the use of synthetic nitrogen to grow crops was fundamental to the farming industry's ability to produce food. "Nitrogen has a key place in feeding populations around the world," he said.

Earlier the 100 delegates from 30 countries had heard Dr Mark Sutton, of the UK's Centre for Ecology and Hydrology, pointed to a doubling of "reactive nitrogen" since the late 1940s.

This type of nitrogen included ammonia emissions from fertiliser and livestock and was made worse by emissions of nitrogen oxides from fossil fuel combustion. "Much of that type of nitrogen goes up into the atmosphere where it disperses, but it then contaminates natural ecosystems," he stated.

Picken countered that farmers were "alive to the environmental impact that nitrogen use has and appreciate the need for timely and targeted applications of fertiliser".

He continued: "Optimising the uptake of nitrogen by plants is not only good for the environment, but makes good business sense. Fertiliser is now a very expensive input and, with more efficient application, farmers have reduced the amount of nitrogen currently being used on farm to levels last seen in the 1970s."

But Dr Albert Bleeker, of the Energy Research Centre in the Netherlands, said the problems were predicted to get worse with nitrogen emissions continuing to increase. "The over-fertilisation effect represents and major threat to global biodiversity."

Picken pointed out that new varieties of grass and cereals were more efficient in uptake and use of nitrogen and there was a role for science to ensure "we have the knowledge that can best exploit plant genetic development and fertiliser requirement to its fullest potential".

He said current farming methods reflected a more responsible attitude towards fertiliser use. The use of buffer strips, water course protection, properly calibrated fertiliser spreaders and so on were good examples of best practice regularly found on farms.

He stated that in an era of high fertiliser prices, clovers and other legumes were increasingly incorporated into grassland and cropping systems, reducing reliance on artificial nitrogen.

"Of course, there are huge areas of hills and uplands that never see a fertiliser spreader, yet provide the necessary grazing for many of the cattle and sheep that are extensively reared in Scotland. Those livestock are managing our habitats and carbon-rich soils and producing food in an inherently sustainable fashion."A broad-brush policy approach to nitrogen might make some good headlines, but Scotland provides ample proof that issues around the environment and climate change are complex and often require greater insight than simplistic solutions.

"Nitrogen usage is only part of a wider picture that has seen overall emissions from agriculture in Scotland decrease by 23 per cent in the past 30 years."