Can water pollution from farming be reduced?

A great deal of work has been done to promote water protection in agriculture. Despite this, excessive quantities of soil and nutrients (nitrogen and phosphorus) keep being leached from fields into water bodies. What is the outlook like?

Agriculture is the greatest culprit for eutrophication in Finnish water bodies: more than one half of anthropogenic nutrient emissions come from farming. Nutrients are leached from fields into water bodies especially when the ground is bare. Leaching is driven by meltwaters and floods in spring, and autumn rains later in the year. Climate change is exacerbating the situation especially in Southern and Central Finland, where the period with snow cover is becoming shorter and winter rains are increasing.

A number of methods are used in efforts to reduce nutrient leaching. Good soil condition in arable fields is important, as this means that plants efficiently take up any fertilisers spread in the field. Field drainage is additionally being replaced by more comprehensive water management schemes. This promotes better retention of nutrients in catchments.

The work carried out to protect waters has started to bring results: especially the phosphorus loading has been reduced successfully. Additional efforts are needed, however. More efficient and accurately targeted water protection measures as well as farming methods that help prevent loading of water bodies must be introduced.

Science has also come up with completely new ways of reducing emissions. They include incorporating gypsum or soil-improving fibres into fields. Both of these substances are produced as industrial side streams. Gypsum and fibres improve soil structure and reduce erosion, which prevents phosphorus bound in soil particles from being transported into water bodies. Structural liming of clay soils also reduces phosphorus leaching.