Monitoring and Assessment of Impact of Nutrient Management Measures Dr. Antanas Sigitas ŠILEIKA Water Management Institute

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

Nutrient load to the Baltic Sea N, tonsP, tons Country Denmark Estonia Finland Germany Latvia Lithuania Poland Russia Sweden 83,000 59,000 72,000 14,000 94,000 19, ,000 81, ,000 68,700 46,500 66,000 21,400 91,000 36, ,800 84, ,900 5,300 2,800 3,400 1,200 3,200 1,700 15,000 9,500 4,000 2,600 1,300 3,600 0,600 2,200 1,400 14,200 7,100 4,700 TOTAL661,000760,70046,10037,700 N load has increased 100,000 tons

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

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 N leaching from Nemunas basin 6 times less than from Denmark

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

AVG NO3-N Concentration, mg/l > 4.1 mgN/l

NO 3 - N changes in the agricultural and background rivers Period of agr. reform.

Duckweed in the r. Nevezis

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.

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

Monitoring and Assessment Method 1. Demonstration watersheds in the areas vulnerable to nitrate pollution and built on previous BAAP and other works; 2. Topography, soils characteristics and land use GIS data base in watersheds; 3. Advanced manure handling in animal farm and nutrients balance on fields and farms; 4. Monitoring of agricultural runoff, precipitation, water quality in dug wells.

WatershedTotal area, km 2 Arable, % Pasture, % Forest, % Graisupis Vardas Lyzena Bariunai0.24Farm Yard 0.10 Characteristics of demonstration watersheds

Vardas Bariūnai Graisupis Lyžena Location of Monitoring Watersheds

Watersheds Graisupis post Vardas post Lyzena post

Opening of the DF

Monitoring post

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.

NO 3 -N load from watershed, kg ha yr TotalAVG r. Graisupis Ditch Crop Pasture Rainfall Largest load from crop

NO 3 -N concentration in r. Nevezis (upstream Kedainiai) and Graisupis

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

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.

N cycle on farm N losses

N and P input in soil of dem. farm Input, kg ha Fertilizers & seeds Fodder and animals Deposition & fixation Manure71014 Total I PN

Crop yield NH3 evaporation750 Leaching Denitrification Total II Total I-Total II (x) Residues (y) x–y =deficit/oversupply N and P output from soil, kg ha -1 DeficitOversupply

Field Trials

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

Grassland management and NO3- N leaching to drainage, kg ha -1 Before ploughing After ploughing

Slurry in Lithuanian large farms

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

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.

Barn watershed Monitoring post Manure storage Cow barn

Barn territory before manure storage construction

Layout of manure handling system Manure pad Surry pit Cow barn

Manure storage, slurry reservoir and rain water management

Filling of slurry spreader

Slurry spreading by trailing hoses

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

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

Manure storage capacity and financing need for farms > 10 AU Number of farms – Ctl 1450 and Pig 49 Manure pads need – Ctl thou m 2 Slurry reservoirs need – Ctl thou m 3 and Pig 39.8 thou m 3 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

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

Water improvement in dug well Permitted limit