Factors controlling the export of nitrogen from agricultural land in a large central European catchment during 1900−2010

0394494 - BC 2014 RIV US eng J - Journal Article
Kopáček, Jiří - Hejzlar, Josef - Posch, M.
Factors controlling the export of nitrogen from agricultural land in a large central European catchment during 1900−2010.
Environmental Science and Technology. Roč. 47, č. 12 (2013), s. 6400-6407. ISSN 0013-936X. E-ISSN 1520-5851.
[ASLO 2013. New Orleans, 17.02.2013-22.02.2013]
R&D Projects: GA ČR(CZ) GAP504/12/1218
EU Projects: European Commission(XE) 244121 - REFRESH
Institutional support: RVO:60077344
Keywords : reactive nitrogen * mass budgets * agricultural land * forest * modelling
Subject RIV: DJ - Water Pollution ; Quality
Impact factor: 5.481, year: 2013

Using an empirical model, we quantified the nitrogen (N) export from agricultural land in a large central European catchment (upper Vltava river, Czech Republic, about 13 000 km2) over the 1959−2010 period. The catchment witnessed a rapid socio-economic shift from a planned to a market economy in the 1990s, resulting in an abrupt 50% reduction in N fertilization rates at otherwise relatively stable land-use practices. This large-scale experiment enabled disentangling and quantification of individual effects of N fertilization and drainage on N leaching. The model is based on a two-step regression between annual N export and three independent variables: (i) annual average discharge in the first step and (ii) net anthropogenic nitrogen inputs (NANI) and proportion of drained agricultural land in the second step. Results show that N export was more related to mineralization of soil organic N pools due to drainage and tillage than to external N sources (NANI). The model, together with other reconstructed N sources in the catchment (leaching from forests, waste waters, and atmospheric deposition) and extrapolated back to 1900, explained 77% of the observed variability in N concentrations in the Vltava river during the 1900−2010 period.
Permanent Link: http://hdl.handle.net/11104/0222702