Monitoring and Assessment of Impact of Nutrient Management Measures

1. Monitoring and Assessment of Impact ofNutrient Management Measures Dr. Antanas Sigitas ŠILEIKA Water Management Institute Sigitas@water.omnitel.net 20040914

2. The problem • Status Report on Implementation of the 1988 Ministerial Declaration reveled that non of the HELCOM Contracting Parties had achieved the overall N and P load reduction target of 50 % to the Baltic Sea

3. N load has increased 100,000 tons Nutrient load to the Baltic Sea

4. 1986 1988 1990 1992 1994 1996 1998 2000 2002 Year 3,736 7,144 5,273 4,727 7,980 6,654 5,727 1,078 1,664 NH4-N, t 14,978 15,131 14,727 27,596 32,753 23,193 39,661 27,205 37,383 NO3-N, t 5,845 1,780 2,972 1,561 1,723 0,979 1,128 0,592 1,076 PO4-P, t NO3-N load has increased 2.5 times Nutrient load to the Baltic Sea from the r. Nemunas in Lithuania Source: Monitoring annals of the Lithuanian Joint Research Centre. Calculation for the Nemunas basin from Smalininkai post

5. N leachingfrom Nemunas basin 6 timesless than from Denmark Nitrogen load from agriculture in rivers of Finland, Germany, Denmark and Lithuania Source: Sustainable Agriculture and Forestry (BERNET Report), 2000 Monitoring data of the Lithuanian Joint Research Centre

6. Agricultural Production, N Fertilization in Lithuania, NO3-N Concentration in Agricultural Rivers Production % Concentration mg/l Fertilization %

7. AVG NO3-N Concentration, mg/l 1996-2001 > 4.1 mgN/l

8. Period of agr. reform. NO3- N changes in the agricultural and background rivers

9. Duckweed in the r. Nevezis

10. Nutrient concentration in rivers • Phosphorus concentration dropped down below eutrophication level 0,05 mg/l; • Ammonium nitrogen concentration now is below permitted limit 0,39 mg/l; • Meantime concentration of nitrate nitrogen increased and still is higher than before 1990 in agricultural rivers.

11. Rainfall N cycle in watershed Emission Fodder N fixation Leaching Fertilizers Runoff Food

12. Monitoring and Assessment Method Demonstration watersheds in the areas vulnerable to nitrate pollution and built on previous BAAP and other works; Topography, soils characteristics and land use GIS data base in watersheds; Advanced manure handling in animal farm and nutrients balance on fields and farms; Monitoring of agricultural runoff, precipitation, water quality in dug wells.

13. Characteristics of demonstration watersheds

14. Location ofMonitoringWatersheds Bariūnai Lyžena Graisupis Vardas

15. Watersheds Vardas post Graisupis post Lyzena post

16. Opening of the DF

17. Monitoring post

18. Monitoring methods • Thompson weirs are used for flow measurements in streams. Water level is registered automatically by limnigraphs; • The river water samples are taken manually every day. Joint weekly samples are analysed in spring and joint monthly sample at another time of the year; • The concentration of nutrients and average monthly values of the river water flow are used for calculation of nutrient losses; • Tipping bucketsare used for drainage flow measurements.

19. NO3-N load from watershed, kg ha yr-1 Largest load from crop

20. NO3-N concentration in r. Nevezis (upstream Kedainiai) and Graisupis

21. Load from crop Load in ditch Nutrient retention Load in stream Load in river

22. Assessment of watersheds monitoring • The highest N losses (15.3 kg N ha-1) determines more intensive agricultural activity in Graisupis (71.5 kg N ha-1 of fertilisers; 54% of arable land; 0.87 LU ha-1); • Close to the sea (Lyzena) are bigger water discharges in winter but due to low N content in soil (32.9 kg N ha-1 of fertilisers, 74% of grassland) the annual N losses are very small (5.7 kg N ha-1); • The highest P losses (0.318 kg P ha-1) determine Vardas hilly relief and clay soil; • Bigger specific water runoff (0.08 l s-1 ha-1) and light soils (sandy loam) determine comparatively high N losses (11.9 kg N ha-1) despite low farming activity (39.4 kg N ha-1 of fertilisers, 45% of grassland) in Vardas watershed.

23. N losses N losses N cycleon farm

24. N P N and P input in soil of dem. farm

25. Deficit Oversupply N and P output from soil, kg ha-1

26. Field Trials

27. The highest leaching is from row crops N leaching dependence on crop The least leaching is from perennial pastures

28. Grassland management and NO3- N leaching to drainage, kgha-1 After ploughing Before ploughing

29. Slurry in Lithuanian large farms

30. 111 kgN, 12 kgP and 104 kgK produce one cow per year Nutrients in milk production

31. Lithuanian obligations to EU • To establish manure storages on large farms with more than 300 AU as well as on newly established farms having over 150 AU within a 4-year period after entering the EU • All the rest farms with more than 10 AU endangering the environment with nitrates will also have to reconstruct their barns later.

32. Manure storage Monitoring post Barn watershed Cow barn

33. Barn territory before manure storageconstruction

34. Layout of manure handling system Cow barn Surry pit Manure pad

35. Manure storage, slurry reservoir and rain water management

36. Filling of slurry spreader

37. Slurry spreading by trailing hoses

38. Before construction Full pit Total N concentration in drainage water from the territory of barns Permitted limit 12mgN/l Filling

39. Before construction Full pit Total P concentration in drainage water from the territory of barns Permitted limit 1500 micro gP/l Filling

40. Manure storage capacity and financing need for farms > 10 AU • Number of farms – Ctl 1450 and Pig 49 • Manure pads need – Ctl 446.5 thou m2 • Slurry reservoirs need – Ctl 472.7 thou m3 and Pig 39.8 thou m3 • Manure pads construction cost– Ctl 22.5 M EUR • Slurry reservoirs cost – Ctl 50.8 M EUR and Pig 4.6 M EUR • Total cost – 78.0 M EUR

41. NO3-N concentration in 5775 dug wells >10 mgN/l

42. Water improvement in dug well Permitted limit