Modelling Nitrate Reduction Strategies from Diffuse Sources in the Po River Basin

Abstract

Water contamination caused by the presence of excessive amounts of nitrate can be catastrophic for aquatic ecosystems and human health. Due to these high risks, a great deal of emphasis has been placed on finding effective measures to reduce nitrate concentrations in rivers and aquifers. In this study, we used the SWAT model based on grid-cells of 5 minutes of resolution for assessing the processes involved in nitrate loads generation and transport into aquifers and rivers and for providing basin management strategies of nitrate reduction. We applied the model in the Po River Basin (Italy), one of the most densely populated and highly agriculturally exploited area in the Mediterranean basin. The model was successfully calibrated and validated in eight monitoring stations along the Po River for the period 2000–2012. Simulated monthly streamflow and nitrate concentrations were in good agreement with observations, obtaining values of bias around ±25% in both calibration and validation. Among the tested scenarios of nitrogen reduction from agricultural sources, red clover cover crop after corn, coupled with a targeted reduction of mineral fertilizers and the limitation of nitrogen manure leads to a reduction of nitrate leaching and nitrogen emissions of around 37%.

Quantifying Nutrient Budgets for Sustainable Nutrient Management

“…The environmental impacts are not only affected by the amount of nutrient loss quantified in a nutrient budget but also the timing and location of the loss, as well as many ecological factors, such as climate and soil conditions. Therefore, many environmental models have attempted to connect the stakeholder activities with the environmental impacts by simulating ecological processes involved in the emission, transformation, and transportation of the nutrient pollutants (Beusen et al, ; Desmit et al, , Malagó et al, , Schroeck et al, ). However, the wide adoption of environmental modeling approaches by stakeholders is limited by the regions or conditions where the models can be calibrated with data and by the transparency of the modeling inputs and processes (McLellan et al, ).…”

In Search for the Missing Nitrogen: Closing the Budget to Assess the Role of Denitrification in Agricultural Watersheds

“…The Po River catchment, the largest hydrographic system in Italy, covers about one-quarter of the national territory, and it is a strategic area for the national economy, accounting for~40% of the Italian gross domestic product. The Po basin is one of the most densely populated and agriculturally exploited areas in Europe; thus, eutrophication and NO 3 − pollution of surface and groundwater are the most critical consequences in terms of water quality deterioration [24][25][26]. The Po di Volano-Sacca di Goro watershed (925 km 2 , Figure 1) is located in the terminal part of the Po basin, and it is a recently reclaimed deltaic territory included within the administrative borders of the Ferrara Province (Emilia-Romagna Region, Northeastern Italy).…”

An Urban Water Pollution Model for Wuhu City

“…It was challenging to explain the NPS pollution runoff based on specific characteristics, such as land cover. Anna Malagó et al [9] used the Soil and Water Assessment Tool (SWAT) based on grid cells of 5 min of resolution to assess the processes involved in nitrate load generation and transport into aquifers and rivers. It provides basin management strategies for nitrate reduction in the Po River basin (Italy).…”