1. 26 May, 2016 Panevėžys, Lithuania
AGRICULTURAL DRAINAGE AND WATER QUALITY the demand for alternative practices to achieve the balance Arvydas Povilaitis
"Water Management in Agriculture and Environment"
26 May, 2016 Panevėžys, Lithuania

2. Tile Drained Agricultural Land

3. Nutrient losses Nitrate-N 3-20 mg/l from tile-drained fields
Total P concentrations: from 0.1 to 0.15 mg/l
Annual Losses:
- from 3 to 40 kg N/ha
kg P/ha

4. Drainage runoff
Air temperature °C
Drainage runoff mm
Miseckaitė, 2011

5. Golden rule of drainage
„Drain only what is necessary for good trafficability and crop growth – and not a drop more” – any drainage in excess of this rule likely carries away nitrate and water that is no longer available for crop uptake.

6. Conservation Drainage
Management practices that reduce nutrient transport from drained land and not reduce drainage performance:
Controlled drainage
Woodchip bioreactors
Saturated riparian buffer strips
Alternative open ditch design

7. Controlled drainage subirrigation
Effect:
- Reduced drainage outflow
- Increased water retention time
- Increased N uptake by crops
- Denitrification
NO3-N reduction – (30)%

8. DENITRIFICATION BIOREACTORS Woodchips bioreactors
The bioreactor consists of a trench filled with carbon source (woodchips) through which the drainage water is allowed to flow
Wood chips

9. Denitrifying Bioreactor

10. Denitrifying Bioreactor
Bioreactor‘s designed volume
Organic load properties
Microbiological activity
N2O, NO gas emissions
Longetivity
Environmental impact
Costs for Installation and maintenance

11. Laboratory scale tests

12. Laboratory scale tests