Antropogenic input of nitrogen and riverine export from a Mediterranean catchment. The Celone, a temporary river case study

In a catchmnent, nitrogen (N) export from terrestrial ecosystems to rivers is controlled by the hydrological processes and N balance. In the present paper, the soil system N budget and riverine export were quantified in a Mediterranean watershed, the Celone (South-East, Italy). The study area (72km2) consists of agricultural land (70%) and deciduous forests with three small residential areas. Major N inputs derived from fertilizers and animal manure, corresponding for the whole watershed area to 68 and 12kgNha−1yr−1, respectively. N input from point sources was 1% of total input and atmospheric depositions measured in a gauging station near the study area was quantified in ∼6kgNha−1yr−1. Crop N uptake was the main N output from agricultural land; it was estimated in ∼37kgNha−1yr−1 by using data on crop yields provided by local farmers. Total flux of N in surface water was quantified for a year at the outlet of the study area by using continuous measures of flow and discrete measures of N concentrations carried out with a different frequency during the normal and low flow and when floods occurred. The hydrological regime of the stream, which is a temporary river, plays an important role in N transport. Water quality was found to vary considerably through the year in terms of both nutrient concentrations and loads. Riverine N export was quantified in 41% of total N input, and it was mainly transported during flood events, ∼60% of the annual load was delivered during floods occurred in 38 days. Organic nitrogen and nitrate were the main N forms in surface water, and the contribution per hectare was about 24 and 14kgN, respectively. On a yearly basis, the difference between N inputs and outputs including riverine export was estimated in about 4kgNha−1yr−1 for the whole watershed area. This amount partly accumulates in soils in different N forms and the remaining part, mainly in form of nitrate, percolates through unsaturated soil towards groundwater. This study reports an important analysis of N pollution in a Mediterranean watershed with a temporary river system and limited data availability. Data acquisition and handling have proved to be an important challenge to overcome in N balance quantification. The results and the methodology of the present work can be useful for understanding nitrogen loss dynamics and for functional water management and land use planning.

[1]  A. Buffagni,et al.  The lentic–lotic character of Mediterranean rivers and its importance to aquatic invertebrate communities , 2009, Aquatic Sciences.

[2]  Other.  Source apportionment of nitrogen and phosphorus inputs into the aquatic environment , 2005 .

[3]  Josette Garnier,et al.  Water management practices exacerbate nitrogen retention in Mediterranean catchments. , 2016, The Science of the total environment.

[4]  L. Gentry,et al.  Timing of riverine export of nitrate and phosphorus from agricultural watersheds in Illinois: implications for reducing nutrient loading to the Mississippi River. , 2006, Environmental science & technology.

[5]  P. Viaroli,et al.  Nitrogen balance and fate in a heavily impacted watershed (Oglio River, Northern Italy): in quest of the missing sources and sinks , 2011 .

[6]  S. Polasky,et al.  Agricultural sustainability and intensive production practices , 2002, Nature.

[7]  E. Ravagnan,et al.  Variability and fluxes of hydrology, nutrients and particulate matter between the Venice Lagoon and the Adriatic Sea. Preliminary results (years 2001-2002) , 2004 .

[8]  Andrea Buffagni,et al.  A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota , 2012 .

[9]  P. Viaroli,et al.  Soil Budget, Net Export, and Potential Sinks of Nitrogen in the Lower Oglio River Watershed (Northern Italy) , 2011 .

[10]  A. Nissinen,et al.  Total but not high-density lipoprotein cholesterol is consistently associated with coronary heart disease mortality in elderly men in Finland, Italy, and The Netherlands. , 2000, Epidemiology.

[11]  P. Llorens,et al.  THE MIRAGE TOOLBOX: AN INTEGRATED ASSESSMENT TOOL FOR TEMPORARY STREAMS , 2014 .

[12]  David Nash,et al.  A bayesian network for comparing dissolved nitrogen exports from high rainfall cropping in southeastern Australia. , 2010, Journal of environmental quality.

[13]  M. Freppaz,et al.  Catchment features controlling nitrogen dynamics in running waters above the tree line (central Italian Alps) , 2012 .

[14]  Adrian Leip,et al.  Farm, land, and soil nitrogen budgets for agriculture in Europe calculated with CAPRI. , 2011, Environmental pollution.

[15]  G. Trisorio Liuzzi,et al.  Effect of Time Scale on the Performance of Different Sediment Transport Formulas in a Semiarid Region , 2010 .

[16]  D. Barceló,et al.  Mixed effects of effluents from a wastewater treatment plant on river ecosystem metabolism: Subsidy or stress? , 2015 .

[17]  S. Schiff,et al.  Uncertainty in nutrient loads from tile-drained landscapes: Effect of sampling frequency, calculation algorithm, and compositing strategy , 2015 .

[18]  R. Gómez,et al.  Effect of intermittency on N spatial variability in an arid Mediterranean stream , 2009, Journal of the North American Benthological Society.

[19]  J. Hatfield,et al.  Nitrogen in the Environment: Sources, Problems, and Management , 2001, TheScientificWorldJournal.

[20]  Luca Zaggia,et al.  The effect of floods on the transport of suspended sediments and contaminants: a case study from the estuary of the Dese River (Venice Lagoon, Italy). , 2005, Environment international.

[21]  Nicholas C. Parazoo,et al.  TransCom model simulations of hourly atmospheric CO2: Analysis of synoptic‐scale variations for the period 2002–2003 , 2008 .

[22]  Stato ed evoluzione temporale della composizione chimica delle deposizioni atmosferiche nelle aree forestali della rete CONECOFOR , 2014 .

[23]  Donald E. Weller,et al.  Human contributions to terrestrial nitrogen flux , 1996 .

[24]  C. Grignani,et al.  Nitrogen balances at the crop and farm-gate scale in livestock farms in Italy , 2007 .

[25]  Giuseppe Pappagallo,et al.  Temporal variability of suspended sediment transport and rating curves in a Mediterranean river basin: The Celone (SE Italy) , 2015 .

[26]  Ü. Mander,et al.  Indicators of nutrients transport from agricultural catchments under temperate climate: A review , 2012 .

[27]  W. de Vries,et al.  Approaches and uncertainties in nutrient budgets: implications for nutrient management and environmental policies , 2003 .

[28]  Peter Vitousek,et al.  Landscape-level variation in forest structure and biogeochemistry across a substrate age gradient in Hawaii. , 2009, Ecology.

[29]  A. D. Girolamo,et al.  Land use scenario development as a tool for watershed management within the Rio Mannu Basin , 2012 .

[30]  M. Rulli,et al.  Characterising the hydrological regime of an ungauged temporary river system: a case study , 2017, Environmental Science and Pollution Research.

[31]  R. Gómez,et al.  Implications of flow intermittency on sediment nitrogen availability and processing rates in a Mediterranean headwater stream , 2014, Aquatic Sciences.

[32]  V. Smil.  Nitrogen in crop production: An account of global flows , 1999 .

[33]  F. Sabater,et al.  Influence of Land Use on Stream Ecosystem Function in a Mediterranean Catchment , 2008 .

[34]  Ettore Capri,et al.  Assessment of nitrate contamination risk: The Italian experience , 2009 .

[35]  S. Fazi,et al.  Responses of Benthic Bacteria to Experimental Drying in Sediments from Mediterranean Temporary Rivers , 2008, Microbial Ecology.

[36]  L. Pieri,et al.  Nitrogen balance in a hilly semi-agricultural watershed in Northern Italy , 2011 .

[37]  M. Bartoli,et al.  Origin and fate of nitrates in groundwater from the central Po plain: Insights from isotopic investigations , 2013 .

[38]  J. Cerhan,et al.  Municipal Drinking Water Nitrate Level and Cancer Risk in Older Women: The Iowa Women’s Health Study , 2001, Epidemiology.

[39]  M. Bartoli,et al.  Nitrogen Budget in a Lowland Coastal Area Within the Po River Basin (Northern Italy): Multiple Evidences of Equilibrium Between Sources and Internal Sinks , 2013, Environmental Management.

[40]  Klement Tockner,et al.  Emerging concepts in temporary‐river ecology , 2010 .

[41]  S. Anthony,et al.  Description of nine nutrient loss models: capabilities and suitability based on their characteristics. , 2009, Journal of environmental monitoring : JEM.

[42]  Classifying low flow hydrological regimes at a regional scale , 2011 .

[43]  A. Haverkort,et al.  Management of Nitrogen and Water in Potato Production , 2001 .

[44]  M. Tagliavini,et al.  Nitrogen balance and losses through drainage waters in an agricultural watershed of the Po Valley (Italy) , 2008 .

[45]  J. Garnier,et al.  Spatialized N budgets in a large agricultural Mediterranean watershed: high loading and low transfer , 2011 .

[46]  R. Howarth,et al.  Riverine nitrogen export from the continents to the coasts , 2006 .

[47]  David Pont,et al.  Intra- and inter-annual variability in the different forms of diffuse nitrogen and phosphorus delivered to seven sub-tropical east Australian estuaries , 2003 .

[48]  S. Fisher,et al.  The influence of storm characteristics on hydrological connectivity in intermittent channel networks: implications for nitrogen transport and denitrification , 2016 .

[49]  Grizzetti Bruna,et al.  Nutrient Discharge from Rivers to Seas for Year 2000 , 2009 .

[50]  G. Senay,et al.  A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data , 2012 .

[51]  Erwin Schmid,et al.  Groundwater nitrate contamination: Factors and indicators , 2012, Journal of environmental management.

[52]  B. Grizzetti,et al.  Assessing nitrogen pressures on European surface water , 2008 .

[53]  A. Roberts,et al.  Assessing nitrogen fluxes from dairy farms using a modelling approach: A case study in the Moe River catchment, Victoria, Australia , 2016 .

[54]  Fayçal Bouraoui,et al.  Changes of nitrogen and phosphorus loads to European seas , 2012 .

[55]  D. Quílez,et al.  Environmental impact of irrigation in La Violada District (Spain): II. Nitrogen fertilization and nitrate export patterns in drainage water. , 2006, Journal of environmental quality.

[56]  Matthias Obermann,et al.  Impact of significant floods on the annual load in an agricultural catchment in the mediterranean , 2007 .