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Nutrient losses from agricultural sources in Latvia Country Report. Viesturs Jansons Latvia University of Agriculture. Diffuse pollution monitoring network in Latvia. Vienziemite Catchment Drainage. Berze
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Nutrient losses from agricultural sources in Latvia Country Report Viesturs Jansons Latvia University of Agriculture
Diffuse pollution monitoring network in Latvia Vienziemite Catchment Drainage Berze Catchment Drainage Mellupite Catchment Drainage Plots Skriveri Catchment Plots Diffuse pollution monitoring station
Monitoring system in Mellupīte Demonstration Watershed Catchment station (measurements:river run-off, drainage plot run-off, surface run-off, weather conditions) Drainage field station (measurements:drainage field run-off) Data loggers and flow proportional automaticalwater sampling in all measurement levels
Mellupite catchment station • Watershed monitoring • 15 drainage plots (0.12 ha) • Surface run-off plot Surface run-off Crump weir • Weather station
Drainage field station Drainage field 12 ha (surface and subsurface run-off)
Small catchment Ntot mg/l 20,00 18,00 16,00 14,00 12,00 10,00 Berze 8,00 6,00 4,00 Mellupite Vienziemite 2,00 0,00 April May May May May May May May May July July July July July July July July March April April April April April April June June June June June June June June October January March March March March March March March February August August August August August August August August October October October October October October October October December January January January January January January January November February February February February February February February December December December December December December December December November November November November November November November November September September September September September September September September Concentrations of N tot in run-off (1994-2001) Average values Berze (blue line) C 7.2 mg/l CV 52% Dr 8.4 mg/l CV 41% Mellupite (green ) C 2.9 mg/l CV 56% Dr 6.2 mg/l CV 35% 1994 1995 1996 1997 1998 1999 2000 2001 Ntot mg/l Field drainage 25,00 20,00 15,00 Vienziemite (red) C 1.7 mg/l CV 68% Dr 1.8 mg/l CV 67% Berze 10,00 Mellupite 5,00 Vienziemite 0,00
Nutrient run-off (Ntot) Berze C 10.4-21.4 kg/ha year Dr 10.8-26.8 kg/ha year Mellupite C 7.4-11.2 kg/ha year Dr 11.5-22.4 kg/ha year Vienziemite C 3.7-8.6 kg/ha year Dr 1.8-6.1 kg/ha year
Nutrient (Ntot) retentiondrainage c small catchment Characteristics of the small catchment's and drainage fields? • size of the watershed • flow regime (sustained ground water flow, surface run-off, drainage run-off) • stream type (slope, shape, bed features) • farming conditions Mellupite Catchment 960 ha Drainage 12 ha (surface and drainage run-off, arable land) Berze Catchment 370 ha, arable land Drainage 77 ha drainage run-off, balanced fertilization) Vienziemite Catchment 590 ha Drainage 67 ha (surface and drainage run-off, grassland)
Agriculture’s contribution to non point source pollution varies widely as a complex function of land use, cropping system, soil type, climate, topography, hydrology, animal density and nutrient management techniques Nutrient run-off (Ntot) and acreage of arable crops, 1994-2001 Source: Position statement on Agricultural nutrient Management and Environment Quality. 2000. Soil Science Society of America.