ABSTRACT
Agriculture is the main activity that is responsible for contributing large quantities of phosphorus and nitrogen to aquatic ecosystems in Finland. Therefore, it is becoming more important to develop ways of decreasing nutrient losses from agricultural areas by modifying cultivation practices and establishing vegetated buffer strips between agricultural fields and watercourses. Experimental plots were set up at Jokioinen in southern Finland to study the water quality improvement function of grass buffer strips (GBS) and vegetated buffer strips (VBS) in reducing soil and nutrient losses. The effectiveness of the buffer strips was studied by comparing loss of nutrients and total solids from planted areas having no buffer strips (NBS). The total solids lost from the GBS (1100 kg/ha) and VBS (900 kg/ha) were less than the total solids lost from the areas with NBS (1500 kg/ha). The sediment-adsorbed phosphorus loadings were 20 and 36% lower where the GBS and VBS, respectively, were used compared to the loading in the NBS plots. However, the loss of orthophosphates in the spring snowmelt was very high from the plots with VBS as compared to the plots with GBS and NBS. The nitrogen loss from the GBS (6 kg N/ha) was nearly half that with NBS. Buffer strips with dense vegetation can be effective in minimizing pollution of watercourses in agricultural areas.
