| THE INFLUENCE OF AGRICULTURE ACTIVITY ON SURFACE WATER STATUS IN LITHUANIA Laima Cesoniene1; Daiva Sileikiene1; 1VYTAUTAS MAGNUS UNIVERSITY, Kaunas, Lithuania; PAPER: 36/Ecosystems/Regular (Oral) SCHEDULED: 15:55/Wed. 30 Nov. 2022/Arcadia 2 ABSTRACT: It is the opinion of many authors that one of the most important and essential sources of diffuse river contamination is improper farming [1-3] Riversides are a strategically advantageous location for agricultural activities since river floodplains are exceptionally fertile. However, the diffuse contamination from farms is caused by not only the riverbank activities but also the intensive farming throughout the river basin. In pursuit of a larger yield, farmers intensively use manure, various chemical fertilizers and pesticides. However, these materials are easily washed out from the soil by rainwater, which then contaminate rivers with the groundwater or surface runoff wastewater. It has been determined that approximately 30-35% of nitrogen and 10-15% of phosphorus, two main contaminates of the surface waters, originate from agricultural activities [4]. The aim of this research was to evaluate the influence of agricultural activities on the state of surface water in Lithuania. Based on the studies conducted in 2014-2019, only 20 % of the studied lakes (total of 40 lakes studied) do not meet the criteria for good ecological status (0.100–0.140 mg/l) according to the phosphorus (Pb) concentration in water. At lakes Latežeris and Luksnėnai the concentration of Pb indicated a bad ecological class (0.231–0.470 mg/l), while at lakes Draudeniai, Paežeriai and Mastis these indicated very bad class (0.231–0.470 mg/l). The lake Talkša and in ponds Bubliai and Stepanioniai were in average ecological class (0.141–0.230 mg/l). The load of biogenic material in the Lakes basins was calculated using SWAT model data. It has been determined that the largest amounts of nitrogen and phosphorus in the Lakes basin appear due to agricultural activities. |
