REDUCTION OF SEDIMENT, PHOSPHORUS AND NITROGEN TRANSPORT ON VEGETATED BUFFER STRIPS

The largest source of phosphorus and nitrogen in surface waters is cultivated soils. The effects of ten-meter wide grass buffer strips (GBS) on sediment and nutrient losses from cropped soil plots have been studied for one year at the Agricultural Research Centre in Finland. The GBS plots were compared to plots without vegetated buffer strips (no-VBS). The GBSs decreased loads of total solids, phosphorus and nitrogen by an average of 23, 6 and 47%, respectively. The grass buffer strips were effective in autumn but not in spring. Thirty-eight percent more soluble phosphate phosphorus was leached from the GBS plots than from the plots without GBSs, because of their inefficiency in spring.