Impacts of “greening” on eutrophication in the Baltic Sea

Torbjörn Jansson1 , Hans E. Andersen3, Bo Gustafsson 4,  Berit Hasler2, Lisa Höglind1


1 Swedish University of Agricultural Sciences, Uppsala, Sweden

2 Aarhus University, Roskilde, Denmark

3 Aarhus University, Silkeborg , Denmark


Continued actions are needed to reduce eutrophication in the Baltic Sea, especially nutrient reductions from the agricultural sector, as agriculture continues to be the most important source of diffuse nutrient loads into the Baltic Sea. The excessive nutrient loads into the Baltic Sea can, to a large extent, be explained by agricultural loads constituting 60-70% of the loads, and coherence between agricultural and environmental developments is necessary to combat eutrophication. There is a large number of EU- and other regulations that set out to reduce nutrient loads: BSAP (the Baltic Sea Action Plan), WFD (the water Framework Directive) and the Nitrates Directive. The most important policy for the development of agriculture in this region is the EU Common Agricultural Policy (the CAP). The latest CAP reform from 2013 aims to link farmers’ financial support with the provision of public goods and externalities by introducing the so-called ‘greening’ requirements.

However, the environmental effects of the greening requirements and corresponding support are small, suggesting there is room for more efficient ways of achieving the targets.  One method is to decrease nutrient losses by increasing the utilization of the fertilizer and manure application, and this might reduce emissions to both air and water. In this study, undertaken as part of the BONUS Go4Baltic project, we investigate the c and environmental effects of alternatives to the greening requirements, which could be superior in terms of achieving nutrient load reductions.

Applying a chain of three numerical models, the study comprises simulations of the farm sector and environmental effects of incremental reforms involving the following elements:

  • removing the greening requirements, to get a measure of the effect of it
  • improving manure storage capacity, allowing for better timing of application
  • improving manure application technologies
  • increasing the share of liquid manure, which can be applied more efficiently.

The manure handling measures impact on the availability of crop nutrients in manure. The CAPRI model is used for modelling the farm economic adjustments and consequences on land use and nutrient consumption. Those results are used as inputs in a nutrient transportation model computing riverine loads of nutrients to the Baltic Sea. In the final step, those loads are fed into a marine ecosystem model of the Baltic Sea, BALTSEM (Long-term large scale eutrophication model), computing the impacts on selected environmental indicators.The environmental effects considered are the nutrient loads to the Baltic Sea, the effects on eutrophication of the Baltic Sea basins as well as the emissions of greenhouse gases.

The analysis finds that the effects on the environment of removing the greening would be small, which is in line with previous studies. We also estimate the saved costs of removing the greening requirement to be significant, since approx. 30% of the national farm envelopes are tied to this requirement. Therefore, there is scope for considerable economic and environmental gains from removing the greening requirements and replace them with the other measures that bring more substantial environmental benefits.