Arable production systems in the Italy (Grassed or intercropped olive groves):
   The study sites have been selected in a hilly area of Central Italy, Umbria region, catchment of river Paglia.  see details
 
 Arable production systems in the Netherlands :
Arable farms in the Netherlands are organized into crop rotations in which a succession of different crops is repeated every certain number of years..see details
 
 Tunisian production systems: Grombalia aquifer :
The study site is located in the Cap Bon Peninsula, north-eastern of Tunisia. see details
 
 Arable production systems in Germany :
The Selke catchment is a tributary of the Bode River and can be described as a mesoscale, lower mountain range catchment which drains an area of ca. 463 km2. see details
 
 Arable production system in Egypt :
The Study site is located at the Fayoum governorate, Egypt, the only western desert depression (Oasis) connected to River via tributary of “Bahr Yousef”. see details
 
 Arable production system in Denmark :
The production system in Denmark is the Combined Food and Energy system (CFE), located at the experimental farm in Taastrup (55°40'N, 12°18'E) under Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen in Denmark. see details