Anne Falk Øgaard
Seniorforsker
(+47) 958 40 040
anne.falk.ogaard@nibio.no
Sted
Ås - Bygg O43
Besøksadresse
Oluf Thesens vei 43, 1433 Ås (Varelevering: Elizabeth Stephansens vei 23)
Vedlegg
CV 2018Biografi
Utdanning/kompetanse: Doktorgrad (Dr. Scient.) i jordfag fra Norges landbrukshøyskole i 1995.
Arbeidsområder:
-Kilder til fosfortap fra jordbruksarealer
-Resirkulering av fosfor i organisk avfall
-Plantetilgjengelig fosfor i organiske resirkuleringsprodukter
-Jordanalyser
-Planteernæring
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
In agricultural areas dominated by subsurface drainage, leaching of phosphorus (P) from soils is a concern for downstream water quality. Still, the role of chemical processes in subsoils and organic soils in influencing dissolved P leaching needs to be clarified for better predicting the P leaching. In ten mineral and organic soils, we examined a wide range of chemical characteristics including various P pools and sorption–desorption properties at different soil depths and related those characteristics to leaching of dissolved P at the drain depth in an indoor lysimeter experiment. Results showed significant correlations between different P pools (R2-adj = 0.61 to 0.98, p < 0.001) and between sorption capacity measurements (R2-adj = 0.60 to 0.95, p < 0.001). Some organic soils followed the same patterns in P sorption capacity and P lability as sandy soils but some did not, suggesting organic soils differ among themselves possibly due to differences in origin and/or management. Flow-weighted mean concentrations of dissolved reactive P and dissolved organic P depended on both the labile P pools (labile inorganic and organic P pools, respectively) in the topsoil and P sorption and desorption characteristics in the subsoils. Mass-weighted whole-profile degree of P saturation based on the ammonium lactate extraction method (DPS-AL) was an excellent indicator of flow-weighted mean concentration of total dissolved P (FWMC-TDP) (R2-adj = 0.93, p < 0.001). Two profiles, one with organic soils overlaying on sand and the other with sandy soils in all layers, had the greatest FWMC-TDP among all profiles (316 and 230 µg/L versus 33–84 µg/L) due to the same reason, i.e., large labile P pools in the topsoils, low P sorption capacity in the subsoils, and high whole-profile DPS-AL. All results point to the need to include subsoil characteristics for assessing the risks of dissolved P leaching from both mineral and organic soils. Also, the study suggests the need to investigate further the roles of the origin and management of organic matter and organic P in influencing P lability and dissolved organic P (DOP) leaching, as well as the bioavailability of DOP in recipient waters.
Divisjon for miljø og naturressurser
Mitigation measures for phosphorus and nitrogen under changing climate: conflicts and synergies
Nutrient concentrations, loads and stoichiometry (i.e., N:P ratio) in agricultural runoff affect the quality of surface waters. In Norway, the reduction of nutrient runoff is challenged by the sloped landscape, variable weather and changing climate with an increasing number of extreme hydrological events. Mitigation measures for reducing nutrient losses are pressingly needed but they do not always work simultaneously or equally for both N and P, due to the differences in their agronomic and biogeochemical characteristics and dominant transport pathways.
Divisjon for miljø og naturressurser
Tiltak mot fosfor- og nitrogenavrenning i et endret klima: konflikter og synergier
Næringsstoffkonsentrasjoner, tilførselsmengder og støkiometri (dvs. N:P-forhold) i jordbruksavrenningen påvirker vannkvaliteten i vassdragene. I Norge utfordres tiltakene for reduksjon i næringsstoffavrenning av hellende terreng, varierende vær og skiftende klima med et økende antall ekstreme hydrologiske hendelser. Tiltak for å redusere tap av næringsstoffer er nødvendig, men de virker ikke alltid samtidig eller likt for både N og P, på grunn av forskjellene i deres agronomiske og biogeokjemiske egenskaper og dominerende transportveier.