Anne Falk Øgaard
Senior Research Scientist
(+47) 958 40 040
anne.falk.ogaard@nibio.no
Place
Ås O43
Visiting address
Oluf Thesens vei 43, 1433 Ås
Attachments
CV 2018Biography
Education: Dr. Scient in soil science at Agricultural University of Norway in 1995.
Areas of expertise:
-Sources for phosphorus runoff from agricultural fields
-Recycling of phosphorus in organic waste
-Plant-available phosphorus in organic waste products
-Soil analyses
-Plant nutrition
Abstract
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.
Authors
Miguel Las Heras Hernandez Francis Isidore Barre Nils Maximilian Dittrich Avijit Vinayak Pandit Anne Falk Øgaard Daniel B. MüllerAbstract
No abstract has been registered
Abstract
This report shows results from an experiment where it was investigated whether a powder of freeze-dried microalgae (Phaeodactylum tricornutum) had a biostimulating effect on the growth and content of nutrients and antioxidants in basil (Ocimum basilicum). The effect of the microalgae powder was tested as a supplement to either mineral fertilizer or a commercial organic fertilizer. We found no significant effect on the yield of applied microalgae powder, but there was a tendency for a higher yield with added microalgae powder for the treatment with organic fertiliser. This may be due to additional nitrogen supply with the microalgae powder. With mineral fertiliser, there was the opposite tendency, highest yield without microalgae powder. The only statistically significant effect of the microalgae powder was an increase in the concentration of boron for the treatment with organic fertiliser. This was probably an effect of a significant additional supply of boron with the microalgae biomass. There was a tendency for an increased concentration of copper with the addition of microalgae powder with both mineral and organic fertiliser, although the additional copper supply with the microalgae powder was small. With organic fertiliser, there was also a tendency towards increased phosphorus and potassium concentrations with the addition of microalgae powder. This could be a biostimulating effect as the additional phosphorus and potassium supply with the microalgae powder was small, but as mentioned, the effect was not statistically significant. We found no significant differences between the treatments for total antioxidant content.
Division of Environment and Natural Resources
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.
Division of Environment and Natural Resources
Climate- and environmentally friendly use of animal manure
There is a need to update knowledge about the utilization and loss of nitrogen and phosphorus from livestock manure in order to assist the authorities and the agricultural industry in meeting climate and environmental targets. There is a major focus on the use of phosphorus, phosphorus content in soil and runoff to waterways in connection with the revision of the fertilizer regulations. The time and method of spreading livestock manure, as well as the total amount of manure used, are important factors that influence the loss. Reduced ammonia volatilization and runoff of nitrogen reduces indirect nitrous oxide losses from livestock manure, but also direct and indirect nitrous oxide emissions through reduced use of mineral fertiliser. The project includes a literature compilation and field measurements to measure the utilization of nutrients at different spreading times for livestock manure in different parts of the country. In the project, field measurements will be made on the effect of different spreading times on the utilization of nitrogen and phosphorus for plant growth. The field measurements are carried out in Rogaland, Vestland and Trøndelag county.