Air quality and industrial farming
Artificial nitrogen fertiliser is having an increasingly distressing effect on natural ecosystems, impacting soil health and biodiversity.
Paul Simon’s recent article in the Guardian, “Wildflowers lose out twice from nitrogen pollution” emphasises these overlooked environmental impacts.
The use of artificial nitrogen fertiliser damages soil, wildlife and hedgerows. When artificial nitrogen enters the soil, habitats can become increasingly unsuitable for native plant life, which can have a harmful effect on some native wildflower species and the broader ecosystem.
Research by the University of Illinois indicated that in certain circumstances the use of nitrogen can cause the loss of soil organic matter, concluding that: “Long-term sustainability may require agricultural diversification involving a gradual transition from intensive synthetic nitrogen inputs to legume-based crop rotations.”
Such negative impacts should warrant better regulation and restrictions on the use of artificial nitrogen fertiliser. However, the air quality crisis in the UK creates even more impetus for action.
How do we address the air quality crisis?
While discussions on air quality tend to focus on vehicle emissions, farming is a serious contributor to air pollution too. Due to air pollution regulations, total UK emissions of nitrogen oxides have fallen by about 70% over the last two decades. However, there have only been small decreases in UK ammonia emissions (NH3), of which agriculture accounts for about 82%. The current parliamentary inquiry into air quality in the UK provides an important opportunity to address air pollution from agriculture – as the Soil Association set out in our written evidence to the committee.
Impacts of artificial fertilisers
The high use of artificial ammonia fertilisers by UK agriculture significantly contributes to the levels of nitrogen in the air, which increases air pollution. Nitrogen compounds from artificial fertilisers drift over industrial regions and combine to form solid particles that can stick in the fine lung tissue of children and adults and cause negative health impacts.
By imposing stricter targets on the application of artificial nitrogen fertilisers in the UK, the UK Government would be able to dramatically improve the air quality and reduce pollution. These policies should be delivered through the forthcoming Agriculture Bill and the development of new post-Brexit farm policy and future support payments in the UK.
The Government additionally should, through the forthcoming Agriculture Bill, incentivise the use of legumes as cover-crops by farmers with the effect of reducing the use of artificial nitrogen-based ammonia fertilisers. Nitrogen can be naturally added into the soil by legumes that have the ability to “fix” nitrogen from the air and store it in nodules in their roots. This nitrogen can be released or use by subsequent crops. In organic farming systems, these crops are used as cover-crops to draw nitrogen into the soil and provide nutrients to the plant.
Ammonia and animals
Despite the significant impact of artificial fertilisers on air pollution, livestock is the dominate cause of ammonia emissions. In the UK, half of ammonia emissions come from livestock bio-solids of cattle, and 14% comes from poultry. The emissions are most commonly associated with industrial livestock production methods since emission rates increase at higher stocking densities. Emissions resulting from livestock kept in organic and free-range systems are consequently lower since the stocking density in organic systems is reduced.
If the Government wants to address air pollution that result from ammonia, it should support and promote a wider shift towards more environmentally-sustainable farming systems (such as organic) that have higher animal welfare standards and lower stocking-densities. It should also consider strengthening the manure management protocols and enforcement measures to reduce bad practices in UK agriculture while supporting the efforts of farmers who have adopted sustainable methods.
How can I take action?
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