Research and development of agricultural and forestry load reduction measures  

 

Excessive external nutrient load leading to eutrophication is one of the most common challenges in Finnish surface waters. Functionable water protection measures are required to tackle this issue. Turku University of Applied Sciences has carried out studies to provide needed information on the effectiveness and operation of agricultural and forestry load reduction measures. In addition, several research and development projects have been implemented to create new and more efficient water protection measures. 

Experts of the Water protection and restoration team have executed RDI-projects on different load reduction measures such as constructed wetlands, chemical phosphorus precipitation in streams, agricultural drainage treatment with biochar filtration and structure lime. Effects and operation of lake restauration measures have also been studied by the team. For example, the operation of aeration units at Lake Kakskerta was studied during in 2009.        

 

Direct phosphorus precipitation 

Possibilities of the chemical phosphorus precipitation have been studied in small nutrient load hotspot diches as well as in small river scale. Projects Active Wetland, Waterchain and Phosphorus precipitation in streams provided important information on the operation and efficiency of the direct P precipitation of running water bodies. It was shown that direct phosphorus precipitation is efficient way to convert readily algae available dissolved phosphorus into non algae available form. However, caution is needed in the dosing of the chemical to avoid harmful pH changes in the water body.              

 

Structure lime 

Structure lime is an example of nutrient load source control measure. This agricultural load reduction measure is fit for clay soils with poor soil structure. The effectiveness of the measure has been studied in the project Structure lime as agricultural water protection measure.  

The study was carried out in cooperation with multiple research organizations, and it was funded by Finnish environmental ministry. The project included laboratory studies as well as field test in catchment area and field scale. First results are very promising, and studies continue at field study sites to provide reliable information on the measures long term effectiveness.     

 

Our projects:

Rakennekalkki maatalouden vesiensuojelukeinona (2019-)

Sirppujoen vedenlaadun ja tulvasuojelun parantaminen (2018-2019)

Waterchain: Vedenlaadun hallinnan kokonaisuuden kehittäminen Aurajoen valuma-alueella (2015–2018)

Aurajoen ravinnesaostus: Jokimittakaavan fosforisaostuksen testaaminen (2015–2016)

 

Publications:

Kaseva A., Laine K., Ajosenpää T., Niemi J., Mononen M. 2020: Biohiili- ja hakesuodattamo salaojavesien käsittelyssä : pilotoinnin tulosraportti 2019.