Nitrogen and Fertilisers (Episode 5)

That is operative

As an elixir. I cannot be weaned

Off the earth’s long contour, her river-veins.

Down here in my cave

– From Antaeus, by Seamus Heaney

There is something I wanted to be clear about up front. In these conversations, farmers can often feel very targeted and therefore alienated from whole discussion from the beginning. The difficult thing to confront is that in some ways they are the target, or at least a major one of a small number. If I can be forgiven for oversimplifying for a second. When trying to change the impacts of land use in Ireland there are three main streams. Firstly you’ve got domestic or residential and infrastructure. This effects how people build their homes, how those homes draw down resources and deal with waste. This gets managed through planning permissions, building regulations, sewage networks, septic tanks and electricity, and dozens of other elements. Secondly, state owned land. The Irish state is the largest landowner in the country and its holdings include over 50% of commercial forestry, former commercial cutaway bogs run by Bord na Móna, all the nature reserves and national parks, and many, many other things. The third is agriculture, which is one of Ireland’s biggest industries and land uses.

Now you’ll have noticed that the first two streams I define are both focused on the state and government regulation and both will involve multiple departments and overlapping but separate state agencies. They’re complex and that gives the people in charge quite a lot to hide behind and anyone trying to improve things a lot to fight their way through. Usually even trying requires background knowledge or expertise. On the other hand, everyone thinks they know what a farm is. By the virtue of being the only part that people understand, farms become the part that everyone remembers.

There is an unfairness to that and I try to acknowledge it when I can. I’m sympathetic to people’s frustration of seemingly being held to a higher standard than the government itself. However, just because there can be an unfairness to the level of focus or blame, does not mean that there aren’t serious issues that need to be addressed and changes that need to be made. Equally, many people calling for those changes don’t always understand the day to day practical implication of what they want to put into place, which leads to further frustration.

I’m primarily talking about practices that apply to livestock agriculture in this episode. I clarified this firstly, because forestry is also covered by the Dept. of Ag and sometimes its not always clear whether forestry is being included in a particular dataset. For things like water pollution both livestock agriculture and forestry are potential pressures on water quality, sometimes figures on the subject present the two together and sometimes separately. It’s worth checking any statistics you’re using or reading. Secondly, I’m clarifying that I’m not unpicking the debate on livestock numbers in this episode.

Nitrogen is one of the three main fertilisers types used in Ireland. Nitrogen, Phosphorus and Potassium, shortened to N, P, and K respectively. Potassium is usually labelled as Potash if you see it for sale. Nitrogen and Phosphorus are usually the two pointed to when issues of pollution come up, in particular run-off from fields into water courses.

If nitrogen and phosphorus are both found in watercourses, and are often caused by the same processes, why is there a focus in the media on nitrogen fertilisers? Primarily it’s because nitrogen is also a source of emissions.

When nitrogen evaporates and becomes a gas its known as nitrous oxide or N2O and it is a very powerful greenhouse gas. Like I said in the pilot episode, we tend to convert everything to carbon equivalent figures for simplicity because CO2 is the most abundant emission but one tonne of nitrous oxide is equivalent to 298 tonnes of carbon dioxide.

Nitrous oxide lives in the atmosphere for over a hundred years and not only has that very severe greenhouse effect but also actively depletes ozone. While the Vienna Convention that I’ll talk about next week, has been a huge success story in terms of halting damage to the ozone layer, that success has become its own problem. People remember the ozone layer as something we were all really worried about in the 90s and early 2000s that isn’t talked about anymore. That leads people to assume it was never a big deal rather than it was very serious and so action was taken and that action was successful.

People can be forgiven for not assuming positive environmental action was taken on an international scale.

Nitrous oxide is more commonly known as laughing gas, of funny American post-dentist viral videos fame. It was also a popular rave drug in Ireland for a long time, that’s making a comeback, and if you’ve ever seen one inch metal cannisters among litter in the woods, now you why.

But in terms of atmospheric emissions, N2O isn’t coming from dentists or ravers, it’s coming from nitrogen-based fertilisers. Globally, about 1% of all the nitrogen fertiliser applied to the soil to grow our food is emitted to the atmosphere as nitrous oxide. 1% doesn’t seem like much, but it’s sufficient that according to the Irish Environmental Protection Agency N2O contributes to 9.4% of our carbon equivalent emissions overall.

Those are the climate factors, that have been true a long time, but they’ve been particular prominent in the news lately because of rising prices. The war in Ukraine led to a global surge in the price of natural gas. Many people don’t realise that natural gas is the feedstock for creating ammonia, a source of nitrogen for plants. Ammonia is also involved in the production of chemical phosphorus and potassium fertilisers. Between January 2021 and January 2022, fertiliser prices in Ireland rose by 127%. By April of that year it was at nearly 180%.

That has begun to come down again this year, the Central Statistics Office released figures in August saying that fertiliser prices in the country had reduced by 45% on the previous year, but that still leaves them much higher then before this spike.

You would think the skyrocketing prices together the environmental factors would have prompted very rapid change, since the situation seems like a lose, lose. Yet unfortunately, it is once again not that simple.

One issue that slows change in situations like this, is that people treat market fluctuations very differently than they treat government regulation or policy change. If twenty years ago any government had proposed a fifty percent environmental tax on vehicle fuels that would have led to the collapse of that government. The market price has risen that much in the same period though and people are expected to drive the same amount to function socially and economically. There is this sense that market values are a natural force outside of our control, ironically like the weather, therefore we have to work within that framework while actions taken by our government are unfair impositions.

The perception that our national government is something being done to us, while economic factors influenced by global geopolitics is a norm, is a larger issue than just one of fertilisers and likely too large for the scope this podcast today.

But outside of that, is that fact that our agricultural model is based a species of grass which requires these fertilisers, and the scale of change required is continuously underestimated and under-supported.

Perennial ryegrass is the most commonly sown grass species in Ireland. It’s used in livestock pasture all around the country and it regrows after grazing, up to a certain point. All the three of the previously mentioned fertilisers, nitrogen, phosphorus, and potassium, are recommended to use when grazing animals long term on ryegrass swards as well as lime to effect soil ph. Sward is a term used a lot in documents or advice around grass and pasture, and it just refers to the area of grass in question and the upper layer of topsoil it’s rooting in.

Traditional pasture fertiliser in Ireland is slurry. I only recently learned that the term slurry in agricultural sense is not universally understood. Slurry is dilute animal manure. Unlike chemical fertilisers it contains multiple nutrients, but at less consistent levels.

Media and policies seem to frequently confuse the issues of nitrous oxide emissions with chemical nitrogen use. It’s important to point out, that once nitrous oxide is in the atmosphere it isn’t particularly relevant whether it came from slurry or chemical fertiliser. There is a human bias towards something organic, like slurry from manure, as opposed chemical, being inherently greener. I tend to approach any use of “chemical” like it’s a bad word with extreme scepticism and it often reflects a poor understanding of the science or a deliberate distraction. Equally water pollution can come from slurry as well as chemical fertilisers.

The advantage of slurry, isn’t its wholesomeness, which anyone who’s every cleaned out a diary shed can promise you, but that it’s an unavoidable byproduct of livestock in the first place. It has to go somewhere and so can take the place of an inorganic fertiliser that’s created through a fossil fuel heavy process.

When I went to see if there been any studies done in Ireland comparing the likelihood of leaching or run-off from chemical fertilisers versus slurry I could not find anything. Work on the subject seemed to be focused on encouraging farmers to take up what Teagasc are calling Low Emission Slurry Spreading or LESS.

The majority of farms use tractor drawn tankers with splash plates to spread slurry. If you’re lucky enough to have never have been up close to a splash plate, the name tells you all you need to know.

However just in the last year there been a big uptake in adoption of the LESS method as part of farmers reducing the amount of chemical nitrogen they were buying, in particularly on diary farms. In 2022 75% of slurry was applied to land using LESS equipment on diary farms versus 34% of cattle farms. This is considered a major factor in the reduction of emissions from these farms declining in the last twelve months. There is still a journey for Teagasc in reaching their goal to have 90% of farms overall using these methods by 2027.

Farm emissions fell in 2022 and the credit for that was largely placed on reduced chemical nitrogen fertiliser use. Emissions even fell on dairy farms where on average the herd size increased.

While it’s encouraging that improving in this direction could make a real impact, I was not surprised that uptake generally hasn’t been faster though, the more I read into it. The LESS method requires different machinery than the old tanker and splash plate method. Farm machinery is a big investment and so the government set up a scheme to offer grants. But these grants only apply to the purchase of this machinery and they only cover at most 60% of the cost.

Most farmers, particularly smaller farms, don’t own equipment that they only use seasonally, but instead rent it either from leasing companies or neighbours. That kind of grant best benefits farms that already had half the cost of the goods to hand and means that they’re likely be able to rent that machinery out at a profit, meanwhile the farms that didn’t have the extra capital don’t get any state assistance at all.

Then there’s the advice on timing slurry spreading as part of the LESS method. I read several documents that Teagasc provide containing sometimes vague, sometimes conflicting advice on the best timing. What I could gather is that best practise calls for the soil temperature to above 6 degrees, but not so hot and sunny that it oxides the nitrogen too quickly, but equally it can’t be heavy rain or have the soil be saturated. One set of guidelines just said when conditions were “suitable” and did not elaborate. While I’m sure the Goldilocks window of does exist somewhere in mid April, I refer back to the issue of farms sharing equipment when timing is so significant.

As well as applying fertilisers differently, there’s also the process of reducing their use altogether by phasing out the species that so relies on them, perennial ryegrass. That’s when you hear people talking about mixed-swards or multi-species pasture.

The Foley farm near Tallow in Waterford, drew quite a bit of media attention two years ago after they successfully phased out chemical nitrogen use on their land, while maintaining it as a high output diary farm. The farm produces around 8,000 litres of milk per cow per annum, which is well above the national average, and saved nearly €40,000 in 2021 on fertiliser and associated costs.

The process, as reported, began with switching to a multispecies sward approach in 2018, bringing in different varieties of grasses, clovers, and herbs while slowly decreasing chemical nitrogen use. 2021 was the first year applying no chemical nitrogen to grazing ground and farm yields didn’t drop. Reports that I read said chemical fertilisers so I assume that some organic fertilisers like slurry were still use, but it wasn’t specified.

This week nitrogen fertilisers re-entered the news when the EU ended the nitrogen derogation given to Ireland after a lot of contention. For many years, Ireland has been permitted to go above EU levels, but that was threatened due to falling Irish water quality. Two of Ireland’s influential lobby groups, the Irish Farmer’s Association (IFA) and the Irish Creamery Milk Suppliers Association, came out strongly that the derogation should be upheld regardless of the fact that water quality standards were not being met.

It’s worth pointing out here that derogation, a word meaning an exemption from or relaxation of a rule or law, is referring not to a reduction in what is considered that standard upper limits, but a reduction in the amount of special treatment Ireland was already getting.

The IFA and Creameries Association leaders could be accused of using somewhat inflammatory language during this debate, since IFA president Tim Cullinan wanted the Agriculture Minister Charlie McConalogue to “show his teeth” and Pat McCormack of Creameries didn’t think the minister had come back from Brussels with enough scars from the battlefield.

I hope if nothing else in this episode, I’ve demonstrated that this is a nuanced issue and so would hope we could avoid taking that kind of polemic stand in any direction. Though my personal view is that rural water quality most effects rural communities.