Project properties

Title Struvite as an alternative for artificial phosphorus fertilisers?
Group Soil Chemistry and Chemical Soil Quality
Project type thesis
Credits 36
Supervisor(s) Gerwin Koopmans and Walter Schenkeveld
Examiner(s) Prof. dr. Rob Comans
Contact info Gerwin Koopmans
Begin date 2022/05/09
End date 2022/11/09
Description In the Netherlands, we flush about 10 million kg of phosphorus (P) through our toilets each year, which is about double the amount of P used as artificial fertiliser. Phosphorus can be recovered from waste water as struvite (MgPO4NH4-6.H2O) in the form of very small crystals. There are already seven waste water treatment plants producing struvite in the Netherlands. However, it is still unclear whether struvite can be used as an alternative to artificial P fertilisers (e.g., superphosphate) without affecting crop yield.

To use struvite as an alternative for superphosphate, more knowledge is needed on the ability of plants to use struvite as a source of P. In contrast to superphoshate, struvite is not water-soluble which is why struvite is often referred to as a slow-release P fertiliser. However, it is well-known that plants excrete root exudates and acidify their rhizosphere and may as such be capable of solubilising and utilising struvite in an effective manner. Moreover, P availability in soil is strongly affected by adsorption of P onto iron oxide particles meaning that differences in P-solubility between P-fertilisers may level-out after being brought in equilibrium with soil.

You will set-up and perform a pot experiment with maize on P-deficient soil in which you compare P uptake between plants grown on soils fertilised with struvite, superphosphate and an organic fertiliser. You will interpret the results from soil- and plant analyses and try to elucidate whether different P-fertilisers (i) differently affect P-availability in soil and (ii) affect P uptake of maize plants.

This MSc Thesis topic is a joined project of Wageningen University (chairgroup SOC) and Wageningen Environmental Research (WEnR, formerly known as Alterra). You will be supervised by Gerwin Koopmans from SOC and Inge Regelink from WEnR.
Used skills Setting up lab experiments and chemical soil analyses, data processing and interpretation, and writing
Requirements 12 credits of SOC/SBL-courses in either one of the following combinations: 1) SBL-21806 Soil Quality and SOC-34806 Applications in Soil and Water Chemistry; 2) SOC-21306 Soil Pollution and Soil Protection and SOC-34806 Applications in Soil and Water Chemistry; 3) SBL-35306 The Carbon Dilemma and SOC-34806 Applications in Soil and Water Chemistry.