Climate change has a dangerous twin that is killing the UK’s countryside even more quickly.July 16, 2018
Press release Monday 16th July 2018
We know that climate change is exacting a catastrophic impact across the planet and upon the UK’s wildlife, but running in a clear parallel is another system in chaos – the earth’s nitrogen cycle. As we and our politicians grapple to understand the huge upset in the carbon cycle, exacerbated by our excessive consumption, little attention is focused on this equally dangerous phenomenon. And its being fuelled in the fields of our countryside.
Chris says ‘This is simply not on people’s radar, even most environmentalists are not aware of the enormous danger this imbalance represents, and yet its effects are plain to see. I’m certain that over the next ten days we will find that the excessive use of nitrogenous fertilizers is having a disastrous impact on the UK’s wildlife.’ He adds ‘Human production of fixed nitrogen is now five times higher than it was just 60 years ago, and the planet has never had this much fixed nitrogen ever in its history. The potential consequences are every bit as terrifying as climate change.’
Chris Packham’s Bioblitz started on Saturday 14th July. For 10 days, he and a team of experts will be visiting 50 wildlife sites in Scotland, Northern Ireland, England and Wales to highlight the extent to which the nation’s wildlife is under threat.
One of the threats facing our wildlife is the addition of chemicals to our countryside, including nitrogen.
Nitrogen is a naturally occurring element, which nature can capture from the air for free – provided suitable plants are present. Some plants, especially in the pea family, can naturally convert nitrogen present in the air, into a different form of nitrogen, which plants – and animals – use to make their own cells. It’s been around 100 years now since scientists worked out how to convert naturally occurring nitrogen in the air, into nitrogen fertilizer. Estimates suggest that half the world’s food supply is now produced using artificial nitrogen fertiliser.1
Now, this might sound like an O-Level or GCSE flashback… for many people the nitrogen cycle was something they learned for an exam and then forgot all about. But there’s big money in fertilizers, in understanding nitrogen. The problem with these nitrogen-based fertilizers, particularly on farmland, is that only a proportion of the nitrogen applied is taken up by the crop, or target plants, the rest escapes into the wider ecosystem via aerial pollution, into the surrounding soils, or into water courses via run-off. The surplus affects wildlife in different ways.
A detrimental effect on waterways and birds
Rain causes excess nitrogen to wash off fields into watercourses. It enters rivers and causes algal blooms, which, in turn, affects birds and other wildlife, including in Poole Harbour, an internationally important site for birds. Paul Morton from Birds of Poole Harbour, is very concerned about the impact of nitrogen entering the harbour.
“We need to get to grips with how much nitrogen is entering Poole Harbour. From what we can see, it’s having a real effect on the intertidal areas which are so important for feeding birds. Thick mats of algae are covering the large areas of productive mud, where the birds feed. There’s no way to remove it.”
Problems in the ground
Back to the science lesson… As well as the crops where the nitrogen is applied, there are some wild plants, which can take up additional nitrogen in the soil very well, but this is at the expense of the majority which cannot. This is why many farm woodlands, hedge-banks and road verges are now dominated by rank grasses, nettles, docks, hogweed and cow parsley, all of which soak up the excess nitrogen, and then out-compete their neighbours.
Nitrogen use is bigger than you think
Defra recently published the latest statistics on nitrogen use on English farmland. Despite claims by the National Farmers Union2, application rates have not declined between 2012/13 and 15/16 (the most recent figures). Average application rates on farmland are 113kg of nitrogen per hectare.3
Farmers find natural way to solve the issue
Scientists have recognised for decades, that too much nitrogen in the environment (technically known as eutrophication) is a big problem, for people’s health and for nature. But despite some actions like the EU’s Nitrates Directive4, the problem has not gone away. Farmers who grow food organically do not use artificial nitrogen fertilizer, but instead finding their fertility from naturally nitrogen-catching crops, and animal manures. Other farmers are using an array of techniques to avoid losing nitrogen from the farm to the environment Martin Lines, of the Nature Friendly Farming Network, said
“We want to maximise crop production and minimise inputs like nitrogen. We’re moving over to having cover crops which will mop up any nitrogen which the arable crop doesn’t use. These cover crops hold the nutrients between crops and make them available for the next crop”. Lines explained “we have really precise soil mapping for our farm, so we know exactly which soils produce the most yield and apply fertilizer so the crop only gets what it needs. We don’t want to lose anything from the system. We then use wildflower and bird seed margins around all our watercourses, so these will mop up any nitrogen which does leave the field.”
The purpose of the Bioblitz
This might seem like nothing new… so why is it still an issue? Why is this threat not being addressed at a fast enough rate to preserve our wildlife on a nationwide scale?
During the course of the Bioblitz, Chris and his team will be raising awareness of some of the threats affecting our countryside, our wildlife, and looking for solutions that people can implement to bring about change.
The Bioblitz campaign has a scientific purpose too. The results of this 2018 audit will be recorded to create a benchmark; this will help measure the rise and fall in numbers of different species in the future. By knowing what’s actually happening in our countryside, we can all work together to find ways to protect it for future generations to enjoy.