Nutrients: which agricultural measures make sense?

This project is part of the Water Quality Knowledge Impulse. Agriculture plays a major part in the nutrient loading in our waters. In this project we are studying the effects of measures that farmers could take to reduce nutrient losses to ground water and surface water. We also examine how we can use the results of monitoring and system knowledge to increase farmers’ water-awareness and their action perspectives.

What is the problem?

In the Delta plan Agricultural Water Management (DAW) farmers and water managers work together on improving water quality and stimulating biodiversity through sustainable agricultural practices. At the moment, however, we don’t have sufficient knowlegde about the hot spots and hot moments of nutrient emissions across a catchment area, since the national and regional water quality measurement networks are too sparse. This makes it difficult to work with farmers in taking well-founded DAW measures. We also lack knowledge about the effects of measures under local conditions (depending on the crop, soil, agricultural plan and water management).

The current knowledge about measures to be taken is based on expert judgement or model analyses and, only in a few cases, on field research. The report ‘Succes- en faalfactoren Agrarisch Waterbeheer’ (Success and failure factors in Agricultural Water Management) by Breman et al. (2016) indicates that the lack of knowledge about the effectiveness of measures is a failure factor for the DAW.

What are we going to do?

In this project we want to establish a clearer picture of the effectiveness of local measures (where, when, how) that aim at improving the water quality in a catchment area. This calls for knowledge and tools to identify the obstacles and solutions when it comes to groundwater and surface water quality. There must be a broad consensus, for instance, about the methods used in the water-system and source analyses, so as to minimise discussions about methodological differences. Key knowledge questions concern how monitoring and modelling, in combination with new sensor- and data-analysis techniques, can together provide a clearer picture of water and nutrient flows. But also, how the (fragmented) data sources and model tools can be better unlocked and interconnected.

What are the deliverables?

Deeping of system knowledge for strategic appraisals and planning at the catchment-area level, through state-of-the-art measurement techniques, models and knowledge about sources and routes.
Insight in the relation between agricultural management and water quality through integration of data on the field and farm level, in order to provide farmers the opportunity to reduce nutrient losses to ground- and surface water. Spatial and temporal variations are explicitly addressed.
Underpinning of the effects of promising measures in practice, for different combinations of crops, soils and hydrological situations, through field studies and knowledge synthesis. This also includes the improvement of methods for distinguishing the contribution of different sources to nutrients in groundwater in order to determine the perspective on realisation of policy objectives.