| Abstract | In this work, a new nitrogen load apportionment tool was developed to quantify the anthropogenic pressures from point sources and diffuse sources (DSs) on the water in a basin, and to identify the areas contributing most of the total nitrogen (TN). The model, which is an alternative approach to complex conceptual models, was tested in the Canale d'Aiedda Basin (SE Italy). It integrates the TN soil system budget (SSB), TN riverine export (N) and TN export coefficient modelling. The results of the SSB showed a TN surplus for productive land (~60 kg ha yr). Major TN inputs were derived from fertilisers (~89 kg ha yr, 77% of the total input) and animal manure (~13 kg ha yr, 11% of the total input). Crop uptake was the main output (~39 kg ha yr, 70% of the total output). N was estimated through the measurement of streamflow and TN concentrations in two stream sections. The average N per unit area of productive land was 5.22 kg ha yr. Groundwater was the major receptor of the TN from DSs. The TN runoff export coefficients, estimated on the basis of environmental factors and calibrated with riverine load measurements, were lower than the TN leaching fractions. The results show that setting export coefficients based only on environmental factors, without any calibration, leads to an overestimation of TN load in runoff, and to an underestimation of TN load in leaching. |
| Text | 420664 2019 10.1016/j.agwat.2019.105806 Scopus 2 s2.0 85072846595 Nitrogen Soil System Budget riverine nitrogen load Export coefficient model load apportionment model intermittent stream Developing a nitrogen load apportionment tool Theory and application De Girolamo A.M.; Spano M.; D Ambrosio E.; Ricci G.F.; Gentile F. Water Research Institute, National Research Council, Bari, Water Research Institute, National Research Council, Bari, Italy, , , Italy; Water Research Institute, National Research Council, Bari, Water Research Institute, National Research Council, Bari, Italy, , , Italy; Department of Agricultural and Environmental Sciences, University of Bari Aldo Moro, Bari, Department of Agricultural and Environmental Sciences, University of Bari Aldo Moro, Bari, Italy, , Italy In this work, a new nitrogen load apportionment tool was developed to quantify the anthropogenic pressures from point sources and diffuse sources DSs on the water in a basin, and to identify the areas contributing most of the total nitrogen TN . The model, which is an alternative approach to complex conceptual models, was tested in the Canale d Aiedda Basin SE Italy . It integrates the TN soil system budget SSB , TN riverine export N and TN export coefficient modelling. The results of the SSB showed a TN surplus for productive land 60 kg ha yr . Major TN inputs were derived from fertilisers 89 kg ha yr, 77% of the total input and animal manure 13 kg ha yr, 11% of the total input . Crop uptake was the main output 39 kg ha yr, 70% of the total output . N was estimated through the measurement of streamflow and TN concentrations in two stream sections. The average N per unit area of productive land was 5.22 kg ha yr. Groundwater was the major receptor of the TN from DSs. The TN runoff export coefficients, estimated on the basis of environmental factors and calibrated with riverine load measurements, were lower than the TN leaching fractions. The results show that setting export coefficients based only on environmental factors, without any calibration, leads to an overestimation of TN load in runoff, and to an underestimation of TN load in leaching. 226 Published version http //www.scopus.com/record/display.url eid=2 s2.0 85072846595 origin=inward Articolo in rivista Elsevier 0378 3774 Agricultural water management Print Agricultural water management Print Agric. water manag. Print Agricultural water management. Print annamaria.degirolamo DE GIROLAMO ANNA MARIA TA.P04.005.006 Gestione a scala di bacino delle risorse idriche e sostenibilita dell uso irriguo in agricoltura |
