Improved modelling of atmospheric ammonia over Denmark using the coupled modelling system DAMOS

A local-scale Gaussian dispersion-deposition model (OML-DEP) has been coupled to a regional chemistry-transport model (DEHM with a resolution of approximately 6 km × 6 km over Denmark) in the Danish Ammonia Modelling System, DAMOS. Thereby, it has been possible to model the distribution of ammonia concentrations and depositions on a spatial resolution down to 400 m × 400 m for selected areas in Denmark. DAMOS has been validated against measured concentrations from the dense measuring network covering Denmark. Here measured data from 21 sites are included and the validation period covers 2–5 years within the period 2005–2009. A standard time series analysis (using statistic parameters like correlation and bias) shows that the coupled model system captures the measured time series better than the regional- scale model alone. However, our study also shows that about 50% of the modelled concentration level at a given location originates from non-local emission sources. The local-scale model covers a domain of 16 km × 16 km, and of the locally released ammonia (NH<sub>3</sub>) within this domain, our simulations at five sites show that 14–27% of the locally (within 16 km × 16 km) emitted NH<sub>3</sub> also deposits locally. These results underline the importance of including both high-resolution local-scale modelling of NH<sub>3</sub> as well as the regional-scale component described by the regional model. The DAMOS system can be used as a tool in environmental management in relation to assessments of total nitrogen load of sensitive nature areas in intense agricultural regions. However, high spatio-temporal resolution in input parameters like NH<sub>3</sub> emissions and land-use data is required

Governing processes for reactive nitrogen compounds in the European atmosphere

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Correction: Agricultural policies exacerbate honeybee pollination service supply-demand mismatches across Europe

The following information was missing from the funding section: BBSRC, DEFRA, NERC, the Scottish Government and the Wellcome Trust, under the Insect Pollinators Initiative crops project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Economic Costs of Nitrogen Management in Agriculture

Nitrogen (N) management is one of the measures of Annex IX of the revised Gothenburg Protocol and described in detail in the Guidance Document (Bittman et al., Options for ammonia mitigation: guidance from the UNECE task force on reactive nitrogen. Centre for Ecology & Hydrology, Edinburgh, 2014). The measures of Annex IX aim at the abatement of ammonia (NH3) emissions from agricultural sources. This chapter reviews literature dealing with the economic costs of N management, aimed at decreasing the N surplus and increasing N use efficiency (NUE) at farm level. Nitrogen balances are important tools for N management; they are prerequisites for monitoring, reporting and verification. They have been implemented in practice in Denmark and The Netherlands, and are used in many other countries as research tool. The economic costs of making N balances at farm level range between 200 and 500 € per farm per year. Possible additional costs relate to comparing and discussing these balances with other farmers. Also governments make costs for verification and control, estimated at 50–500 € per farm per year

Parameterization Models for Pesticide Exposure via Crop Consumption

An approach for estimating human exposure to pesticides via consumption of six important food crops is presented that can be used to extend multimedia models applied in health risk and life cycle impact assessment. We first assessed the variation of model output (pesticide residues per kg applied) as a function of model input variables (substance, crop, and environmental properties) including their possible correlations using matrix algebra. We identified five key parameters responsible for between 80% and 93% of the variation in pesticide residues, namely time between substance application and crop harvest, degradation half-lives in crops and on crop surfaces, overall residence times in soil, and substance molecular weight. Partition coefficients also play an important role for fruit trees and tomato (Kow), potato (Koc), and lettuce (Kaw, Kow). Focusing on these parameters, we develop crop-specific models by parametrizing a complex fate and exposure assessment framework. The parametric models thereby reflect the framework's physical and chemical mechanisms and predict pesticide residues in harvest using linear combinations of crop, crop surface, and soil compartments. Parametric model results correspond well with results from the complex framework for 1540 substance-crop combinations with total deviations between a factor 4 (potato) and a factor 66 (lettuce). Predicted residues also correspond well with experimental data previously used to evaluate the complex framework. Pesticide mass in harvest can finally be combined with reduction factors accounting for food processing to estimate human exposure from crop consumption. All parametric models can be easily implemented into existing assessment frameworks