|Title||How do soil organic matter characteristics and associated functions develop in organic arable soils over time?|
|Supervisor(s)||Guusje Koorneef, MSc, dr Mirjam Pulleman, dr. Ron de Goede|
|Examiner(s)||Prof.dr .Rachel Creamer|
|Description||Organic farming practices are expected to modify the quantity and quality of soil organic matter (SOM) as compared to conventional farming. In 2017, we collected soils from 76 Dutch organic and conventional farms on sand and marine loam soils. The organic farms comprise a chronosequence, ranging from farms that recently started organic management to farms that have been managed organically for >30 years. Each organic farm was paired with a nearby conventional farm. Soil type, land use history and crop rotation of sampled arable fields were as similar as possible. This setup allows us to compare soil characteristics and functioning of organic fields of different age, as well as organic vs. conventional farming.
We hypothesize that ‘older’ organic soils will have a larger biologically active fraction of SOM compared to conventionally managed soils and soils that have recently been converted to organic. This difference in SOM quality will also lead to differences in the structure of the soil community, and hence its related soil functions as decomposition of different substrates.
You will analyse the collected soil samples with innovative methods to assess the quality of the soil organic matter. Data analysis will focus on the relations between SOM quality and the functioning of soil life, making use of pre-existing data.
|Used skills||- Setting up a new laboratory method
- Soil biological and soil physical laboratory analyses
- Data analysis, interpretation and writing