Nitrate agricultural sources

Council Directive 91/676/EEC of 12 December 1991 concerning the protection of waters against pollution caused by nitrates agricultural sources. Official Journal No. L 375, 31 December 1991, pp. 1-8. Nearly a decade later most of the EU countries are not in compliance with the nitrate directive. 

Directive 91/676/EEC [8] concerning the protection of waters against pollution caused by nitrates from agricultural sources... 

Fig. 1 Results from a redundancy analysis of stream nutrient concentrations vs. catchment characteristics in 31 headwater catchments in Catalonia (Spain). Note how phosphorus (SRP) and ammonium (NH4) appear associated with urban point and diffuse sources (Urban percent urban land use, Inhabs number of inhabitants, eq. inhab inhabitant equivalents), whereas nitrate (NO3) concentration is positively associated with irrigated agriculture (IrrAg) and bovine cattle units (ECU), and negatively with mean catchment slope (slope) and percent forest land (Forest). The other variables are Area log area, P precipitation, NonIrrAg non irrigated agriculture. Data are from the Catalan water agency (http //ww.gencat.cat/ac)...

Nitrous oxide contributes severely to global warming and the depletion of ozone in the stratosphere (Crutzen 1981, Bouwman 1996). Almost 90% of the global atmospheric N2O is formed during the microbial transformation of nitrate (NO ) and ammonia (NH ) in soils and water. In OECD countries the agricultural contribution to N2O emissions is estimated at 58% (IPCC 2001). Soils fertilised with inorganic fertilisers and manure stores are seen as the largest sources (Chadwick et al. 1999, Brown ef al. 2002). 

Pollutants derived from nonpoint sources run-off from agricultural lands (fertilizers, pesticides, humic materials), run-off from urban areas (salt, poly aromatic hydrocarbons [PAHs], asbestos), atmospheric fallout (particulates containing sulfate, nitrate, heavy metals, PAHs, and chlorinated organics). 

---