1. DIAS Nitrate leaching and pesticide use in energy crops Uffe Jørgensen, Danish Institute of Agricultural Sciences, Dep. of Agroecology, Research Centre Foulum

2. DIAS Biomass use and production in Denmark Total energy use 2004 839 PJ Biomass (straw, wood, biogas) 59 PJ Municipal waste 37 PJ Wind power 24 PJ Renewable energy 14% of total energy use Energy crops: 10-20,000 ha. rape & c. 1000 ha. willow

3. DIAS Danish agriculture can produce much more energy – but also have to fulfil … The Water Framework Directive The Ground Water Directive The Habitat Directive The 3rd national action plan on the aquatic environment The national action plan on pesticides Etc.

4. DIAS Annual versus perennial crops Perennial crops have the most efficient nutrient use Perennial crops are hardy and competitive (not during establishment) Therefore, perennial crops are more easy to produce with low environmental impacts

5. DIAS Nitrate leaching from energy crops Measured by installation of suction cups below the root zone

6. DIAS Nitrate leaching from willow Coarse sand 150 kg N 105 kg N 3-9 kg N 13-42 kg N 1-16 kg N

7. DIAS Nitrate leaching from miscanthus loamy sand

8. DIAS Leaching from common agricultural crops on sand PeasWinter barley Winter wheat Oats Winter barley Winter rape Winter wheat 100 80 60 40 20 0 40 60 80 100 120 140 160 180 200 220 100 80 60 40 20 0 40 60 80 100 120 140 160 180 200 220 N leaching, kg per ha Concentration of nitrate-N Apr88Oct88Apr89Oct89Apr90Oct90Apr91Oct91Apr92Oct92Apr93Oct93Apr94

9. DIAS Protection of drinking water on the renewable energy island, Samsø

10. DIAS How much can nitrate leaching be reduced by changing to energy crop production? Energy crops substituteReduced leaching c. Crop rotation:50 kg N/ha. Annual set aside:30 kg N/ha. Grass fallow: -10 kg N/ha. Mean N-abatement cost in the latest national action plan for the aquatic environment: 21 DKK per kg N

11. DIAS Pesticide use in energy crops Quality demands not so crucial for energy use Hardy and competitive crops Weed management is important during establishment of perennial crops Pesticide-free production possible

12. DIAS Mechanical weed management

13. DIAS Annual pesticide treatments in energy crops Triticale 1997-980,9 (0,3 - 1,7) Triticale 1998-990,7 (0 - 0,9) Miscanthus Foulum, 1993-20000,6 (0 - 3,0) Miscanthus Jyndevad, 1993-2000 1,0 (0 - 5,9) Willow Foulum, 1993-2000 0 Willow Jyndevad, 1993-2000 0,4 (0 - 3,0) Mean in Danish agriculture2,2 Reduction target 20091,7

14. DIAS Energy crops can ensure water quality But what about quantity? Willow uses a lot of water! Soil water percolation from winter wheat willow 1993-94522 mm404 mm 1994-95648 mm537 mm 1995-9677 mm0 mm

15. DIAS Miscanthus saves water Soil water content in willow and miscanthus

16. DIAS Conclusions Energy crops and good water quality can be co-produced Perennial energy crops reduce nitrate leaching –by up to 50 kg N/ha –especially efficient in utilising manure and sludge Compared with fallow and afforestation energy crop production secures continued animal production

17. DIAS Willow, poplar & alder

18. DIAS Miscanthus

19. DIAS Reed Canary grass