TaRgEting Low-Sorption Soils to reduce phosphorus losses (TiRELeSS)

Last changed: 23 June 2020
Map over Sweden with red dots mainly concentrated on the islands Öland and Gotland, and parts of Scania and

The project will find risk areas for leaching of dissolved phosphorous. As opposed to particulate phosphorous is dissolved phosphorous always directly available for water living organisms.

Agriculture is a main contributor of nutrients to water recipients and nutrient losses need to be reduced to meet good ecological status according to EU Water Framework Directive.

Losses of phosphorus (P) occur both in forms of dissolved P (DP) and particulate P (PP). While the bioavailability of PP form varies from 10 to 90 %, the DP is assumed to be readily bioavailable. Results from research projects and monitoring programs show extremely high DP losses from soil with small P sorption capacity (PSC).

The project will be performed in four steps:

  • Using results from nation-wide soil survey in combination with other auxiliary geospatial data and results from environmental monitoring programs, we will identify sensitive areas of arable land prone to high DP losses.
  • In the second step we will compare different laboratory methods, P fractionation procedures, XANES and P NMR to quantify P speciation and transformations and thereby develop guidelines for farmers and water authorities regarding identification of high-risk soils.
  • Additionally, using intact soil columns we will study P leaching losses, as well as the effects of P fertilization on small PSC soils.
  • Finally, in the last step we will scale-up our results and develop P leaching risk maps at national scale.

Targeting soils with small PSC will increase cost-efficiency of abatement measures and at the same time identify other areas of arable land which are more resilient and allow intensified agricultural production without threatening water quality.

Map over Sweden with red dots mainly concentrated on the islands Öland and Gotland, and parts of Scania and
Phosphorous sorption capacity of the Swedish agricultural soils. The red dots show the soil samples which had the 10 % lowest phosphorous sorption capacity of totally 12508 soil samples (red and grey dots).

TiRELeSS is lead by Faruk Djodjic at the Department of Aquatic Sciences and Assessment, SLU. The other participants are Lars Bergström and Magdalena Bieroza at the Department of Soil and Environment, SLU, and Yongfeng Hu at Canadian Light Source.

The project receives financial support by FORMAS – A Swedish research council for sustainable development.

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