Minister Christianne van der Wal’s nitrogen plans lead to strong criticism from farmers’ organizations. Also within her own party, the VVD and the CDA, there are calls to adjust the plans. Today there is a large demonstration against the policy at Stroe. Nitrogen experts understand that there is anger and dismay, but maintain that their measurements and models are correct.
Thousands of farmers will gather in the Gelderland municipality of Barneveld this Wednesday to protest against the government’s nitrogen plans. One of their counter-arguments is that the models for nitrogen emissions and the measurements of the actual emissions of nitrogen in natural areas are not correct.
Based on the models presented by the minister on 10 June, the agricultural sector must significantly reduce nitrogen emissions. In some regions, so much nitrogen has to be reduced that it is impossible for some farmers to continue with their business any longer. That causes great unrest.
At a VVD congress – two days after the presentation of the nitrogen plans – a majority of those present (51 percent) voted in favor of the motion to adjust the nitrogen policy, “based on measurements and facts instead of models and calculations”. .
‘We’ve had just about everyone on the phone’
The three scientists who called NU.nl this week have had their telephones active since that conference. The RIVM, which is responsible for nitrogen measurements in the Netherlands, was called down by the media. “We’ve had just about everyone on the phone,” said senior researcher Albert Bleeker. news hour and RTL News showed reports in which RIVM staff took reporters to measuring poles to show that the measurements are really taking place.
Bleeker: “A lot is measured in the Netherlands, more than in our neighboring countries. There are calls to install measuring poles at every agricultural company, but that is not financially and logistically feasible. Our network of measuring poles and other measuring instruments is constantly being expanded, but with what we are doing now you get a sufficient to good picture of nitrogen depositions in the Netherlands.”
Nitrogen deposition means the return of nitrogen oxides and ammonia to the ground. Nitrogen dioxides are released into the air through exhaust gases and emissions from industry. Ammonia comes from animals in livestock farming.
‘Groups try to disprove scientific results’
The term “sufficient to good” comes from the report of the Advisory Board for Measuring and Calculating Nitrogen, led by emeritus professor Leen Hordijk. The previous cabinet set up this committee after the first major farmers’ protests against nitrogen policy in 2019. During that period, doubts arose about the measurement and calculation method for determining nitrogen emissions. “It is good to see that what we want to know is being measured and that we know who is responsible for what contribution,” wrote the then Minister of Agriculture Carola Schouten to the House of Representatives at the time.
The committee did, however, make recommendations to improve the nitrogen measurements. According to Hordijk, these words are “taken out of context” by MPs, especially because most of the recommendations have now been adopted. For example, more measuring poles have been installed, the use of satellite images is being investigated and the nitrogen deposition of traffic is no longer calculated at 5 kilometers from the source, but up to the national borders. This allows better comparisons to be made.
So why the fierce criticism? The emeritus professor draws a comparison between the critics of the nitrogen policy and, for example, the large tobacco industry. “Advocacy groups that can no longer be justified are trying to negate clear scientific results.”
Hordijk expressly distances himself from parties who criticize the RIVM measurements and the underlying models. “We know a lot about nitrogen,” he says. “Of course it can always be more precise, but that won’t fundamentally change the pattern we see now.”
‘You will never get absolute certainty’
That opinion is also of Mark Wilmot. He is one of the people behind the so-called AERIUS model. This calculation tool is used to calculate nitrogen emissions and their precipitation on Natura 2000 areas. Hordijk and his committee subjected this instrument to a critical examination in 2019.
With a team of fifteen people, Wilmot has been refining the model for twelve years. “We receive measurement data from RIVM with which we can check whether the model is correct.” But, he warns: “You will never get absolute certainty.”
In recent years Wilmot and his team have worked closely with representatives of Wageningen University & Research and the Agricultural and Horticultural Organization (LTO) among others. The aim is to have the system match the practice as closely as possible. For example, they investigate the effects of technological measures that farmers take to contribute to the government’s reduction target.
Wilmot emphasizes that not only the Hordijk Committee has looked at AERIUS. For example, research organization TNO has previously assessed the model three times and there has also been an international study. And the model has always withstood the test of criticism.