Shift to sustainable agriculture could benefit rivers

Rapeseed field in Germany. Image: Kris Rae Orlowski on Unsplash

A transition to more sustainable forms of agriculture will benefit rivers, according to an international research team.

Agriculture secures our food supply and is an important economically, but it also leaves its mark on the environment, including soils, groundwater and biodiversity. Led by scientist Christian Schürings, from the University of Duisburg-Essen in Germany, the researchers investigated how different types and intensities of agriculture affect the ecological status of rivers in Europe.

The results were alarming: not even 10% of rivers in Germany are in a good, near-natural state, while across Europe, it is around 40 percent. As the largest land use category, agriculture is considered partly responsible for this situation.

"Our results underline that the transition to more sustainable forms of agriculture, such as organic farming, is beneficial for rivers."

Christian Schürings, University of Duisburg-Essen

The researchers wanted to know if this reputation is justified?

To answer this question, the research team analysed data on agricultural land use for 27 European countries. This was linked to data on the ecological status of flowing waters, including streams, but also large rivers such as the Ruhr, Rhine, and Scheldt.

The discovery was that the type of agriculture does strongly influence the condition of rivers.

"Intensive farming has the greatest impact," says Schürings, an expert in aquatic ecology.

"This includes irrigated agriculture, as practised in southern Europe, for example in Spain, Portugal and Italy, and the intensive use of pesticides and fertilisers on land in western Europe. This is particularly common in France, the Netherlands, Belgium, Germany and the UK."

Intensive farming can have multiple impacts, it can cause nitrate, crop protection products, and other substances to end up in water bodies; floodplains may be converted into farmland; and rivers straightened, or used for irrigation. This threatens or destroys important habitats for plants and animals.

Farming in Spain. Image: Marta Ortigosa on Unsplash

With less intensive types of agriculture, the situation was found to be very different. According to the study, they have little or no negative impact on the ecological status of the environment. The researchers say that this is because the cultivated areas are small-scale, fertilisers and crop protection products are used more sparingly, and hedges and flower-strips are planted for increased biodiversity.

"Our results underline that the transition to more sustainable forms of agriculture, such as organic farming, is beneficial for rivers,"says Schürings.

Co-author Dr Sebastian Birk says that water protection and agriculture go hand in hand: "The EU should support this through a restructuring of agricultural subsidies, so that the environmental services provided by agriculture are more strongly rewarded."

The study was published in the journal Water Research.