Energy crops are protecting Ringkoebing Fjord. Ingeborg Svennevig, Chief Project Manager Ringkjøbing Amt Teknik og Miljø

Catchment area: km 2 Fjord: 290 km 2 Water is regulated by a sluice in Hvide Sande

Objectives County council: visibility between 1½-2 meter HD: good conservation status for nature types and species VRD: good environmental status Users: want to bathe, fish, hunt etc.

Source: Dansk Landbrugsrådgivning Nitrogen influx from land:

Actionplan from the envistigation phase

Våde enge Styrede dræn Skovrejsning8-23 Fytoremediering25100 Gylleseparering? – til miljøet Ændret dyrkning75?? MVJ-ordninger98?? VVM0?? Dambrug36?? Spildevand Andre amter6100 Cost-effective action plan, 1. version Total: tons/år

Våde enge3228 Styrede drænKendes ikke SkovrejsningGratis Fytoremediering2,3( kr./ha i anlæg) GyllesepareringLIFE-miljø? Ændret dyrkning67 kr./ha i 10% af oplandet MVJ-ordningerGratis for amtet VVM0(1 mio. / år ifl. FØI) DambrugPrisen kendes ikke SpildevandMeget dyrt for lidt Costs and (lack of) finanse

Fytoremediering Calculated costs in N-removal

Energy crops, advantages and disadvantages Effect? Crop! – but technique? Which species are adaptable and effective? Will the drains be ruined? Aestetic value? Market?

A B C D E F Sum Bølling (0) Hemmet (  ) Ilderhede (0) Isenvad (0) Mellem Finnerup (+) Nørrekær øst Nørrekær midt (  ) 16 (+) Nørrelandet vest Nørrelandet øst 4 Plantning ikke mulig 4 Plantning ikke mulig 2 Plantning ikke mulig 5 Plantning ikke mulig 4 Plantning ikke mulig 4 Plantning ikke mulig 23 (  ) Rødding (0) Skjern Enge (  ) Spjald (+) Strømmensbøl (+) Sønder Bork Mærskenge (+) Troldhede (0) Vejvad (  ) Velling Mærsk (  ) Vorgod Østerby (+) Ørnhøj (0)

Test area: N-calculation

Objective from the actions plan; removal of N in t/year Potential for N-removal in the pumped areas: t N /år Wetlands Controlled drainage Phytoremedia tion 25100

Arealanvendelse og Jordbundsforhold for Hemmet Bæks opland

- the areas must be dry enough to farm until 15. of October, - the wished level of water must be reached in the begiing of November - the normal farming practice can be re- established around the 1st of March – and the 15th at the latest Criteria for solutions:

Expected effects on the crops Areas with drains higher than 25 cm below ground, cannot hold winter crops. Areas with drains between cm, will not experience reduction in growth – under ”normal” rainfall conditions. Winter crops will not be affected at all, when drains are lower than 50 cm.

Open model Lowest areas will bo floded Pump in action during winter Added water from the land chanel (overrisling) Technical installatioons to lead water from the chanel Closed model Water level: minimum 25 cm below terrain Pump in action during winter No water from the chanel Detail regulated model Water level: minimum 25 cm below terrain Pump in action during winter No water from the chanel Opstemninger i drænkanaler Un-regulated model Maximum water influx No pumping during winter Influx of water from the chanel (floding) Technical installations on the land chanel to make it possible to control the water influx Models for solutions:

Open model Lowest areas will bo floded Pump in action during winter Added water from the land chanel (overrisling) Technical installatioons to lead water from the chanel Closed model Water level: minimum 25 cm below terrain Pump in action during winter No water from the chanel Detail regulated model Water level: minimum 25 cm below terrain Pump in action during winter No water from the chanel Opstemninger i drænkanaler Un-regulated model Maximum water influx No pumping during winter Influx of water from the chanel (floding) Technical installations on the land chanel to make it possible to control the water influx Models for solutions:

Open model Lavestliggende arealer oversvømmes Pumpning i vinterperioden Vand fra landkanal tilledes (overrisling) Overløbsbygværker på landkanal Closed model Vandniveau mindst 25 cm under terræn Pumpning i vinterperioden Ingen vand fra landkanal Detail regulated Model Vandniveau mindst 25 cm under terræn Pumpning i vinterperioden Ingen vand fra landkanal Opstemninger i drænkanaler Un-regulated model Maksimal vandtilledning Ingen pumpning i vinterperioden Vand fra landkanal tilledes (oversvømmelse) Regulerbar indløbsbygværk på landkanal Models for solutions

Open model Lavestliggende arealer oversvømmes Pumpning i vinterperioden Vand fra landkanal tilledes (overrisling) Overløbsbygværker på landkanal Closed model Vandniveau mindst 25 cm under terræn Pumpning i vinterperioden Ingen vand fra landkanal Detail regulated model Vandniveau mindst 25 cm under terræn Pumpning i vinterperioden Ingen vand fra landkanal Opstemninger i drænkanaler Un-regulated model Maksimal vandtilledning Ingen pumpning i vinterperioden Vand fra landkanal tilledes (oversvømmelse) Regulerbar indløbsbygværk på landkanal Models for solutions:

Consequences for agriculture Open modelNo winter crops on the lowest areas, app. 30 ha Closed modelOnly small effects on agriculture, max. 5 ha Detail regulated Model Only small effects on agriculture, max. 21 ha Un-regulated model No more winter crops (of the traditional kinds), app. 62 ha

N-transport, Hemmet Bæk

Average monthly N-transport, Hemmet Bæk

Calculated N-reduction

Maximum potential in all the pumped areas around the Fjord

N-reduction and costs… ModelEffected area (ha) N- removal (kgN/year) Loss in farming (pr. year) Loss (kr./kgN/ year) Costs of technical ities (kr.) Open ? Closed Detail regulated Un-regulated

Åben modelLukket model Detailregule ret model Ureguleret model N fjernelse i tons Kapitaliseret maksimalt driftstab i mio. kr Potential in all pumped areas (6.000 ha)

Denitrifikation Nitrat Nitrit Atmosfærisk kvælstof N2ON2O Lattergas Kvælstofilte N2N2 NONO 2 NO 3

Energien til denitrifikationen Organisk stof + nitrat + brintioner  kuldioxid + atm. kvælstof + vand 5(CH 2 O) + 4 NO H +  5 CO N H 2 O

Effekt?

Conclusion Vintervådlægning af pumpelag resulterer i øget kvælstoffjernelse Ekstern tilførsel af vand forøger kvælstoffjernelsen markant Lavtliggende arealer vil ikke kunne anvendes til vinterafgrøder Afhængig af metode kan kvælstofudvaskningen fra Skuldbøl Enge reduceres med mellem 413 og tons-N/år, svarende til 4–75 kg- N/ha/år Vintervådlægning af alle potentielle pumpelag kan give en kvælstoffjernelse på op til 450 tons-N/år, som forudsat i Handleplanen Der må afhængig af metoden forventes et driftstab på mellem 9-18 og kr./kg-N/år

Arealtilstand efter drændybder