Agricultural Runoff Monitoring in Latvia

Agricultural runoff monitoring in Latvia was initiated in 1994 with the aim to identify and assess the environmental effects of agricultural management practices on water quality. This paper summarizes the key components of diffuse nutrient losses in different spatial and temporal scales. The agricultural runoff monitoring system consists of three monitoring stations at Berze, Mellupite and Vienziemite with hydraulic measurement structures and recording equipment. The monitoring stations are situated in different parts of Latvia and represent regions with different climatic conditions, soil texture, slopes and farming intensity. Long-term data (1995 - 2010) collected during the agricultural runoff monitoring proves that diffuse source pollution from agricultural land, i.e., nitrogen and phosphorus losses into water, depends on anthropogenic activities (intensity of agricultural practices), natural factors (meteorological and hydrological conditions), and scale of measurements (experimental plots, drainage field, small catchment, river).