Work Package 2

Assessment of water and nutrient use efficiency from field to catchment scale

Leader: Prof. Dr. Niels P.R. Anten Organization: Wageningen University (WU) 
Email: Country: Netherlands
1.Develop and validate a crop model approach for our network of production systems,
2.Determine water and nutrient use efficiencies, gaps therein and leakages of the production systems,
3.Develop and validate a hybrid model approach that links field to catchment scale.
Description of work
Concerns about limited availability and pollution of water sources demand that gaps in agricultural water and fertilizer use efficiencies need to be closed. This work package aims to quantify the magnitude of these gaps and identify their causes/drivers in different production systems. This entails a complex task, particularly as different processes and efficiencies therein act on different spatial and temporal scales. Crop yield and resource use efficiency gaps are typically determined by processes at the field level. However, dynamics of water and nutrient movement need to be assessed, and linked to governance, at the catchment scale. In this work package we link these two integration levels. First, we use crop models (WOFOST and DAISY) and field measurements to determine yield gaps as well as water- and nutrient-use gaps in our network of production systems. We then build a blue print for analysing the causes of these gaps, test this in the Netherlands, and consider how this approach can be used in our other production systems. Finally, we link the crop model WOFOST to a hydrodynamic model of water quantity and quality (HYPE) in order to quantify the interplay between processes and interventions at field level and spatial hydrodynamic processes at catchment scale in the production systems of Germany and, possibly, Tunisia.. This will yield a novel model approach that can serve as a tool for other work packages in this project.