GYPSUM INNOVATION FOR EFFECTIVE REDUCTION OF PHOSPHORUS RUNOFF FROM - PowerPoint PPT Presentation

GYPSUM – INNOVATION FOR EFFECTIVE REDUCTION OF PHOSPHORUS RUNOFF FROM AGRICULTURAL FIELDS HELCOM PRESSURE, October 11 th 2018 Marjukka Porvari, John Nurminen Foundation

BENEFITS OF UTILIZING GYPSUM (CaSO4 ·2H 2 O) IN FIELDS Immediate reduction in phosphorus and suspended solids run- off ≈ 50%.  Unlike most other agricultural water protection measures, reduces both  particulate and dissolved reactive phosphorus. According to studies, effect lasts at least five years.  Recycled side- stream gypsum from e.g. fertiliser, sugar and energy  production can be utilized (note: must be free of harmful substances). Cost with recycled gypsum 70 €/kgP - only 1/3 of the other agri-  environmental measures. Ordinary lime- or manure-spreading machinery can be utilised for  spreading. Suitable for clay fields, in the Baltic Sea region especially in Denmark,  Estonia, Finland, Poland and Sweden. Main limitations: not in drainage areas of lakes or ground water areas due to sulfur . Phosphorus reduction potential in Finland estimated to be 200–300  tonnes/year, in the whole Baltic Sea region 1500 - 2000 tonnes/year.

HOW GYPSUM WORKS? Run-off waters Less particulate and dissolved reactive • CaSO 4 ∙ 2H 2 O phosphorus Less erosion • Gypsum leaches out slowly, effect • estimated to last 5 years Soil Dissolution Ca 2+ + SO 4 Improves soil structure 2− • Ionic strength of soil pore water increases Electric double layer surrounding soil particles becomes thinner • Soil particles form larger aggregates → less prone to erosion • Also runoff of dissolved reactive phosphorus reduces, at the same • time phosphorus stays in plant available form + + + Unlike lime (CaCO 3 ) gypsum does not impact soil pH + ++ + + + + + + - - - - - - - - - - - - + + + + + + + + + + - - - + + + + + + - - - + + After gypsum Before gypsum

STRONG EVIDENCE - STUDIED IN FIELD SCALE SINCE 2007 Kemira Growhow (2007): laboratory tests  TraP-project (2007-2013) - SYKE, University of Helsinki, MTT and TTS Research  Laboratory analyses  Field tests in Nummenpää (continuos water quality monitoring) and MTT  research station in Jokioinen Spreading tests  Economic analyses  NutriTrade and SAVE projects (2015 -2018) – University of Helsinki and SYKE  Field application to 1550 ha in the river Savijoki catchment  Continuous water quality monitoring (suspended solids, phosphorus)  Analysis of impacts on trout spawning, fish populations, mussels, water  moss, diatoms, ground waters, phosphorus release from sediments, soil chemistry Analysis of farmers’ views and acceptance of the measure  Vantaanjoki river project (2018-2020)  Field application to 3500 ha in the river Vantaanjoki catchment  Continuos water quality sampling (suspended solids, phosphorus)  Analysis on impacts on trout spawning and fish populations 

More information Policy briefs http://nutritradebaltic.eu/wp - content/uploads/sites/34/2018/05/NutriTrade -Policy-Brief-1-Gypsum-Amendment-  and-Large-Scale- Use.pdf http://nutritradebaltic.eu/wp - content/uploads/sites/34/2018/05/NutriTrade -Policy-Brief-2-Gypsum-Amendment-  and- Policy.pdf Published articles Ekholm, P., Valkama, P., Jaakkola, E., Kiirikki , M., Lahti, K., & Pietola, L. (2012). Gypsum amendment of soils reduces  phosphorus losses in an agricultural catchment . Agricultural and Food Science , 21 (3), 279- 291. https://doi.org/10.23986/afsci.6831 Uusitalo, R., Ylivainio, K., Hyväluoma, J., Rasa , K., Kaseva, J., Nylund, P., Pietola, L., & Turtola, E. (2012). The effects  of gypsum on the transfer of phosphorus and other nutrients through clay soil monoliths . Agricultural and Food Science , 21 (3), 260 - 278. https://doi.org/10.23986/afsci.4855  Jaakkola, E., Tattari, S., Ekholm, P., Pietola, L., Posch , M., & Bärlund, I. (2012). Simulated effects of gypsum amendment on phosphorus losses from agricultural soils . Agricultural and Food Science , 21 (3), 292- 306. https://doi.org/10.23986/afsci.6773 Iho, A., & Laukkanen, M. (2012). Gypsum amendment as a means to reduce agricultural phosphorus loading: an economic  appraisal. Agricultural and Food Science , 21 (3), 307- 324. https://doi.org/10.23986/afsci.6832 Contact information Markku Ollikainen, Professor, University of Helsinki, p. +385 2941 58065, markku.ollikainen@helsinki.fi  Petri Ekholm, Senior Researcher, Finnish Environment Institute, p. +385 2952 51102, petri.ekholm@ymparisto.fi  Eliisa Punttila, Project Manager, University of Helsinki, p. +385 2941 58061, eliisa.punttila@helsinki.fi 