Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas
Understanding nitrogen (N) exchange between cultivated ecosystems and groundwater becomes crucial in the Rolling Pampas where high and variable water table levels are accompanied by increasing N-fertilization rates. Field monitoring of crops, soils and groundwater was combined with modeling to evalu...
| Autores principales: | , , , |
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| Formato: | info:ar-repo/semantics/artículo |
| Lenguaje: | Inglés |
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Elsevier
2020
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| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12123/7177 https://www.sciencedirect.com/science/article/pii/S0167880909002291 https://doi.org/10.1016/j.agee.2009.08.001 |
| _version_ | 1855035809701298176 |
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| author | Portela, Silvina Isabel Andriulo, Adrian Enrique Jobbagy Gampel, Esteban Gabriel Sasal, Maria Carolina |
| author_browse | Andriulo, Adrian Enrique Jobbagy Gampel, Esteban Gabriel Portela, Silvina Isabel Sasal, Maria Carolina |
| author_facet | Portela, Silvina Isabel Andriulo, Adrian Enrique Jobbagy Gampel, Esteban Gabriel Sasal, Maria Carolina |
| author_sort | Portela, Silvina Isabel |
| collection | INTA Digital |
| description | Understanding nitrogen (N) exchange between cultivated ecosystems and groundwater becomes crucial in the Rolling Pampas where high and variable water table levels are accompanied by increasing N-fertilization rates. Field monitoring of crops, soils and groundwater was combined with modeling to evaluate bidirectional flows (from terrestrial ecosystems to aquifers and vice versa) of water and N throughout a 10-year period (1998–2007) of highly variable precipitation (760–1506 mm year−1) and water table depths (6.5 to <1 m). Piezometers at three topographic positions (upland: UP, mid slope: MS, and toe slope: TS; 1740 and 510 m apart) were used to monitor water table depth and phreatic (<14 m), intermediate (35 m) and bottom of the aquifer (45 m) water chemistry. Crop production and soil water and nitrate content were monitored in two agricultural plots (wheat/soybean–corn rotation) where MS and TS piezometers were located. Nitrate concentration in phreatic groundwater was relatively stable and low at UP and MS (<10 mg l−1) but increased sharply at TS (>45 mg l−1) during periods of high water table levels (<3 m deep). Groundwater chloride concentrations increased with depth in piezometers at UP and MS, but showed the opposite trend at TS during periods of high water table levels, suggesting evaporative discharge at this position. The lateral hydraulic gradient (moving energy) between MS and TS ranged from −0.1 to 0.4% and was negatively correlated with water table depth at TS (R2 = 0.23, p < 0.001, n = 79) indicating that groundwater flow towards TS increased as the water table level rose. A capillary transport model (UPFLOW) suggested that at TS groundwater supplied an important amount of water and solutes to crops with corn obtaining approximately half of its water needs (228–413 mm) and one fourth of its N requirement (38–76 kg ha−1) from groundwater. Water and N supply from groundwater may have explained the higher biomass and grain yield in the lower positions of each plot with regard to the rest of the area. Our results suggest that the Rolling Pampas landscapes can switch from a typical recharge behavior to a recharge–discharge one following extended rainy periods that rise water table levels and hydraulic gradients, favoring water and solute transport towards the lower positions of the landscape and local concentration of solutes by groundwater consumption, simultaneously affecting groundwater quality. |
| format | info:ar-repo/semantics/artículo |
| id | INTA7177 |
| institution | Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina) |
| language | Inglés |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | INTA71772021-09-29T10:44:29Z Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas Portela, Silvina Isabel Andriulo, Adrian Enrique Jobbagy Gampel, Esteban Gabriel Sasal, Maria Carolina Hidrología Aguas Subterráneas Evaporación Acuífero Nitrógeno Hydrology Groundwater Evaporation Aquifers Nitrogen Evaporative Discharge Nitrate leaching Región Pampa Ondulada Understanding nitrogen (N) exchange between cultivated ecosystems and groundwater becomes crucial in the Rolling Pampas where high and variable water table levels are accompanied by increasing N-fertilization rates. Field monitoring of crops, soils and groundwater was combined with modeling to evaluate bidirectional flows (from terrestrial ecosystems to aquifers and vice versa) of water and N throughout a 10-year period (1998–2007) of highly variable precipitation (760–1506 mm year−1) and water table depths (6.5 to <1 m). Piezometers at three topographic positions (upland: UP, mid slope: MS, and toe slope: TS; 1740 and 510 m apart) were used to monitor water table depth and phreatic (<14 m), intermediate (35 m) and bottom of the aquifer (45 m) water chemistry. Crop production and soil water and nitrate content were monitored in two agricultural plots (wheat/soybean–corn rotation) where MS and TS piezometers were located. Nitrate concentration in phreatic groundwater was relatively stable and low at UP and MS (<10 mg l−1) but increased sharply at TS (>45 mg l−1) during periods of high water table levels (<3 m deep). Groundwater chloride concentrations increased with depth in piezometers at UP and MS, but showed the opposite trend at TS during periods of high water table levels, suggesting evaporative discharge at this position. The lateral hydraulic gradient (moving energy) between MS and TS ranged from −0.1 to 0.4% and was negatively correlated with water table depth at TS (R2 = 0.23, p < 0.001, n = 79) indicating that groundwater flow towards TS increased as the water table level rose. A capillary transport model (UPFLOW) suggested that at TS groundwater supplied an important amount of water and solutes to crops with corn obtaining approximately half of its water needs (228–413 mm) and one fourth of its N requirement (38–76 kg ha−1) from groundwater. Water and N supply from groundwater may have explained the higher biomass and grain yield in the lower positions of each plot with regard to the rest of the area. Our results suggest that the Rolling Pampas landscapes can switch from a typical recharge behavior to a recharge–discharge one following extended rainy periods that rise water table levels and hydraulic gradients, favoring water and solute transport towards the lower positions of the landscape and local concentration of solutes by groundwater consumption, simultaneously affecting groundwater quality. EEA Pergamino Fil: Portela, Silvina Isabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelos; Argentina Fil: Andriulo, Adrián. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Departamento de Laboratorio de Suelo; Argentina Fil: Jobbágy, Esteban G. Universidad Nacional de San Luis. Instituto de Matemática Aplicada San Luis. Grupo de Estudios Ambientales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina Fil: Sasal, María Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; Argentina 2020-04-30T13:04:04Z 2020-04-30T13:04:04Z 2009-12 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/7177 https://www.sciencedirect.com/science/article/pii/S0167880909002291 0167-8809 https://doi.org/10.1016/j.agee.2009.08.001 eng info:eu-repo/semantics/restrictedAccess application/pdf Elsevier Agriculture, Ecosystems and Environment 134 (3,4) : 277–286. (December 2009) |
| spellingShingle | Hidrología Aguas Subterráneas Evaporación Acuífero Nitrógeno Hydrology Groundwater Evaporation Aquifers Nitrogen Evaporative Discharge Nitrate leaching Región Pampa Ondulada Portela, Silvina Isabel Andriulo, Adrian Enrique Jobbagy Gampel, Esteban Gabriel Sasal, Maria Carolina Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas |
| title | Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas |
| title_full | Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas |
| title_fullStr | Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas |
| title_full_unstemmed | Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas |
| title_short | Water and nitrate exchange between cultivated ecosystems and groundwater in the Rolling Pampas |
| title_sort | water and nitrate exchange between cultivated ecosystems and groundwater in the rolling pampas |
| topic | Hidrología Aguas Subterráneas Evaporación Acuífero Nitrógeno Hydrology Groundwater Evaporation Aquifers Nitrogen Evaporative Discharge Nitrate leaching Región Pampa Ondulada |
| url | http://hdl.handle.net/20.500.12123/7177 https://www.sciencedirect.com/science/article/pii/S0167880909002291 https://doi.org/10.1016/j.agee.2009.08.001 |
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