1	Monitoring and Assessment of Impact of Nutrient Management Measures Dr. Antanas Sigitas ŠILEIKA Water Management Institute Sigitas@water.omnitel.net 2004 09 14
2	The problem
3	Nutrient load to the Baltic Sea
4	Nutrient load to the Baltic Sea from the r. Nemunas in Lithuania
5	Nitrogen load from agriculture in rivers of Finland, Germany, Denmark and Lithuania
6	Agricultural Production, N Fertilization in Lithuania, NO3-N Concentration in Agricultural Rivers
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8	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	N cycle in watershed
12	Monitoring and Assessment Method
13	Characteristics of demonstration watersheds
14	Location of Monitoring Watersheds
15	Watersheds
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 buckets are used for drainage flow measurements.
19	NO₃-N load from watershed, kg ha yr^-1
20	NO₃-N concentration in r. Nevezis (upstream Kedainiai) and Graisupis
21	Nutrient retention
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 cycle on farm
24	N and P input in soil of dem. farm
25	N and P output from soil, kg ha^-1
26	Field Trials
27	N leaching dependence on crop
28	Grassland management and NO3- N leaching to drainage, kg ha^-1
29	Slurry in Lithuanian large farms
30	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	Barn watershed
33	Barn territory before manure storage construction
34	Layout of manure handling system
35	Manure storage, slurry reservoir and rain water management
36	Filling of slurry spreader
37	Slurry spreading by trailing hoses
38	Total N concentration in drainage water from the territory of barns
39	Total P concentration in drainage water from the territory of barns
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
42	Water improvement in dug well