Preconditions for Including the Effects of Urease and Nitrification Inhibitors in Emission Inventories.

Urease and nitrification inhibitors can reduce ammonia and greenhouse gas emissions from fertilizers and manure but their effectiveness depends on the conditions under which they are used. Consequently, it is essential for the credibility of emission reductions reported in regulatory emission inventories that their effectiveness is assessed under real-world conditions and not just in the laboratory. Here, we specify the criteria we consider necessary before the effects of inhibitors are included in regulatory emission inventories.

Assessing nitrate groundwater hotspots in Europe reveals an inadequate designation of Nitrate Vulnerable Zones.

Monitoring networks show that the European Union Nitrates Directive (ND) has had mixed success in reducing nitrate concentrations in groundwater. By combining machine learning and monitored nitrate concentrations (1992-2019), we estimate the total area of nitrate hotspots in Europe to be 401,000 km, with 47% occurring outside of Nitrate Vulnerable Zones (NVZs). We also found contrasting increasing or decreasing trends, varying per country and time periods.

In-vitro method and model to estimate methane emissions from liquid manure management on pig and dairy farms in four countries.

Methane (CH) emissions from manure management on livestock farms are a key source of greenhouse gas emissions in some regions and for some production systems, and the opportunities for mitigation may be significant if emissions can be adequately documented. We investigated a method for estimating CH emissions from liquid manure (slurry) that is based on anaerobic incubation of slurry collected from commercial farms. Methane production rates were used to derive a parameter of the Arrhenius temperature response function, lnA', representing the CH production potential of the slurry at the time of sampling.

Nitrogen inputs by irrigation is a missing link in the agricultural nitrogen cycle and related policies in Europe.

Irrigation, one of the 28 agri-environmental indicators defined in the European Common Agricultural Policy, is often neglected in agricultural nitrogen (N) budgets, while it can be a considerable source of N in irrigated agriculture. The annual N input from irrigation water sources (NIrrig) to cropping systems was quantified for Europe for 2000-2010 at a resolution of 10 × 10 km, accounting for crop-specific gross irrigation requirements (GIR) and surface- and groundwater nitrate concentration. GIR were computed for 20 crops, while spatially explicit nitrate concentration in groundwater was derived using a random forest model.