Sari Luostarinen is a Senior Research Scientist at the Natural Resources Institute of Finland (Luke) and is the current Chair of the HELCOM Agri group
Aren’t nutrients supposed to be good? What’s wrong with nutrients?
Nutrients are vital for humans, animals and the environment as a whole. They are also vital for agriculture and food production. No crops can grow without nutrients. But as with most other compounds, too much in the wrong place causes problems. In our region for instance, the excess of nutrients has led to the eutrophication of the Baltic Sea.
In terms of eutrophication and nutrients, what is the current status in the Baltic Sea region?
The Baltic Sea is a vulnerable sea for many reasons. The nutrients it has received in the past are bound in the sediments and released under certain conditions, causing internal nutrient loading. At the same time, nutrient runoff from current human activities is adding to the problem. Of the latter, many point sources have been reduced, for example due to improved wastewater treatment. But it is more difficult to restrict diffuse loading such as from agriculture. Depending on the weather conditions and due to increasing temperatures, eutrophication and its consequences are worsening. More actions to control the nutrient load are needed.
In general, what would need to be done to curb eutrophication and nutrient inputs, especially in regard to agriculture?
As said, crops cannot grow without nutrients. Both phosphorus and nitrogen need to be available for crops on the fields to achieve good yields. Good yields also mean that most nutrients given as fertilizers end up in the harvested crop and little is lost to the environment. The amount of nutrients spread as fertilizers should be adequate, for instance adjusting quantities depending on the crop, the soil type and its nutrient content, as well as the timing of the spread. The use of animal manure as a fertilizer is the traditional way to recycle nutrients in food production. However, due to segregation of animal and crop production it may be either available in excess or in deficit depending on the region. More precise utilisation of manure nutrients, including replacing mineral fertilization with manure, is important for reducing agricultural nutrient load. Also, other measures, such as reduced tillage, catch crops, water protection zones, are also needed to manage nutrient losses.
What concrete steps is HELCOM currently taking on the nutrient issue from the agriculture perspective?
HELCOM is efficiently driving several measures to reduce agricultural nutrient losses to the Baltic Sea. As an example, HELCOM is preparing the introduction of recommendations for national manure standards. The aim is to ensure the availability of updated, scientifically proven data on manure quantities and nutrient contents in the Baltic Sea countries so that the manure data used in fertilization planning and thus the amount of manure spread on fields becomes more precise. This is expected to reduce nutrient runoff from the fields. Furthermore, on resource efficiency, HELCOM is also preparing a strategy for nutrient recycling in the Baltic Sea Region. Again, the aim is to introduce more efficient measures to make better use of the nutrients already available and to reduce the need to introduce new mineral nutrients into the cycle. For example, this could be achieved by processing manure, different wastes and their by-products into recycled fertilizers.