Monitoring of the Agricultural Run-off in Latvia (1994-2005)

Viesturs Jansons

Professor, Head of Department of Environmental Engineering and Water Management. Latvia University of Agriculture,

e-mail viesturs.jansons@llu.lv

Water balance:Precipitation 700 mm

Evapotranspiration 450 mm

Run-off 250 mm

Latvia - 6.4 million haPopulation - 2.4 million

Agricultural land - 2.4 million ha Drainage - 1.6 million ha

Agriculture and water quality Baltic Sea

HELCOM political goal (1988) to decrease agricultural pollution by 50% has not been reached in most of countries.

HELCOM PLC-4 (2000)

79 % is input from agriculure

78% is input from

agriculture

Monitoring network in Latvia3 non-point source pollution monitoring stations (sites)

Bērze (368 ha, intensive farming, cereals and sugar beets, arable land 80-90 %.). Established 1968 /1994

Vienziemīte (592 ha, low input agriculture, agr. land 79 %, arable land 4-5 %). Established 1948 /1994

Mellupīte (960 ha, average intensity, arable land 60-70 %). Established 1995.

3 point source pollution monitoring points (large animal farms): Vecauce (1000-2000 pigs, 30 ha slurry application field)Ogre (farm closed in 1992, heavily polluted territory)

Bauska (8000 pigs, 50 ha slurry dumping field)

3 non-point source pollution points (small catchments): Auce (53 ha, intensive farming, cereals)Skriveri (890 ha, average intensity of farming)

Bauska (750 ha, intensive farming, cereals, sugar beats)

Monitoring scale (non point pollution)

Mellupite station, one plot 0,12 ha5 treatments x 3 = 15 plots

Soil, plant, nutrient and water relationships could be studied in the plot level, and nutrient leaching from soil with a different application of mineral or organic fertilisers for various crops might be examined in detail.

Mellupite station, 12 ha

Vienziemite station, 67 ha

Berze station, 77 ha

Nutrient losses from arable land might be measured at a field level. Field scale run-off represents are integrated effect of farming practice, crop rotation, application of fertilisers etc. on the water quality.

Mellupite station, 960 ha

Vienziemite station, 592 ha

Berze station, 368 ha

The integrated influence on nutrient run-off of variations in farming practices, erosion, soil and topography within the small catchment might be studied in a better way than in the field scale. In that scale emission rates (loads) that can contribute to the nutrient enrichment of surface water ecosystem can be examined.

Mellupīte monitoring station (BEAROP Project 1994-2000)

H. Structure – Crump weir

Tipping buckets for plot measurements

Small catchment station with inlets from plots and hydraulic structure.

Weather stationSurface run-off plot

Hydraulic structure – V – shape Crump weirBerze station constructed 2006 – BSRP (WB and

GEF project)

Drainage field station

Both surface and drainage run-off

Monitoring technology

Continuous recording of data from sensors (every 3 min) with data loggers, automatical flow proportional water sampling in all measurement points

Measurement equipment - YSI data loggers, powered from solar panels. GSM data transfer with mobile phone from stations to university PC

Ground water monitoringShallow ground water

monitoring since 2005:

10 wells in 3 monitoring sites are equipped with YSI mini data loggers (to, water level sensors)

Depth of the wells is 4-6 m and 14-18 m (unconfined and confined aquifers)

Water sampling (zonde) every 3 months

Monitoring results 1994-2005Average concentrations of the nitrogen in run-off

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

Plo

ts(u

nfe

rtili

zed

)

Plo

ts(n

orm

al)

Plo

ts (

hig

h)

Plo

ts (

solid

man

ure

)

Plo

ts (

slu

rry)

Dra

inag

efi

eld

Sm

all

catc

hm

ent

Dra

inag

efi

eld

Sm

all

catc

hm

ent

Dra

inag

efi

eld

Sm

all

catc

hm

ent

NO3/N Ntot

mg/l

Mellupite monitoring site

Berze monitoring

site

Vienziemitemonitoring

site

11.3 mg/l N/NO3 (Nitrate Directicve)

Monitoring results 1994-2005 Trends of the nitrogen concentrations in run-off

Vienziemīte catchment

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

4,50

N / NO 3 mg/l

Mellupīte catchment

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

16,00

N / NO 3 mg/l

Bērze catchment

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

16,00

18,00

20,00

N / NO 3 mg/l

1994 2005

11.3 mg/l N/NO3

(Nitrate Directicve)

Monitoring results 1994-2005 Pollution load (Ntot) from agricultural land in Latvia

6,0

8,9

15,3

0

5

10

15

20

25

19

94

19

95

19

96

19

97

19

98

19

99

20

00

20

01

20

02

20

03

20

04

20

05

Av

era

ge

Ntot kg/ha year

Vienziemite catchment Mellupite catchment Berze catchment

Load = Concentration x discharge

Wastewater

One population equivalent

13 g of Ntot day-1

or

4,7 kg Ntot year-1

Measures to decrease pollution?

EU Nitrate directive - Action plans in VZ

Rural development plan - Agro-environmental Schemes

• Green land 50% (30%)

• Nutrient balances in farms

• Buffer zones

• Manure storage

Buffer Zones

Buffer Zones Results of the Latvia Agro-environmental Scheme, 2005

AE measure “Buffer Zones”

Payment, Euro/m

No of the applications

Length of the (m)

“Buffer Zones” Drainage channels, 4 m

0.102 160 165 493

Arable land, fields, 4 m

0.18 57 102 274

Water reservoirs, rivers, 10 m

0.256

126

62 583

Total 343 33035

Improvement of Manure Storage in the VZ. Results of Latvia Agro-environmental Scheme,

2005

Size of farm

Number of farms

Total volume, m3

Solid manure, m3

Slurry, m3

1-10 AU 9 2040 1640 400

10-49 AU 35 28500 19900 6800

50-99AU 7 11600 3200 8400

100-250 AU 8 31200 22900 8300

>250 AU 3 15900 1800 14100

62 89240 49440 38000

BSRP project - 3 storages (1 under construction). Investments 50-100%.