TY - JOUR
T1 - Nitrogen legacies in anthropogenic landscapes
T2 - a case study in the Mondego Basin in Portugal
AU - Marques, João
AU - Liu, Joy
AU - Cunha, Maria C.
AU - Van Meter, Kimberly J.
AU - Basu, Nandita B.
N1 - Funding Information:
WaterJPI—WaterWorks2015 ERA-NET Cofund 2016 Joint Call, Fundação para a Ciência e a Tecnologia (FCT), WATERJPI/005/2016; 3599-PPCDT. Authors (JM and MCC) also acknowledge the support of national funds through FCT, under the project UID/EMS/00285/2020.
Publisher Copyright:
© 2021, The Author(s).
PY - 2022/4
Y1 - 2022/4
N2 - Nitrogen (N) legacies have built up in anthropogenic landscapes over decades of agricultural intensification, and these legacies lead to time lags in water quality change measurable even beyond the moment of application of N. It is important to understand these legacies to quantify the relationship between N inputs and N concentrations in streams and implement best management practices for water quality improvement; however, little is known about the magnitude of legacies in various landscape elements like soils and groundwater. Here, we have used the ELEMeNT (Exploration of Long-tErM Nutrient Trajectories) model to explore the buildup and depletion of N legacies over a 216-year period, across the Mondego River Basin, a 6645-km2 watershed in Portugal, where human interventions have considerably changed the characteristics of the basin to prevent floods and improve farming conditions in recent decades. The results show that the increase in the amount of inorganic fertilizer applied was the main driver for the anthropogenic N loads in the watershed from 1950 until the beginning of the 1990s. The N inputs have been decreasing since then, but N loads in the river did not document any decrease till the 1990s; after which there was a decline. This time lag between the N inputs to the watershed and the N loads in the river (about two decades) is a function of accumulation of N legacy.
AB - Nitrogen (N) legacies have built up in anthropogenic landscapes over decades of agricultural intensification, and these legacies lead to time lags in water quality change measurable even beyond the moment of application of N. It is important to understand these legacies to quantify the relationship between N inputs and N concentrations in streams and implement best management practices for water quality improvement; however, little is known about the magnitude of legacies in various landscape elements like soils and groundwater. Here, we have used the ELEMeNT (Exploration of Long-tErM Nutrient Trajectories) model to explore the buildup and depletion of N legacies over a 216-year period, across the Mondego River Basin, a 6645-km2 watershed in Portugal, where human interventions have considerably changed the characteristics of the basin to prevent floods and improve farming conditions in recent decades. The results show that the increase in the amount of inorganic fertilizer applied was the main driver for the anthropogenic N loads in the watershed from 1950 until the beginning of the 1990s. The N inputs have been decreasing since then, but N loads in the river did not document any decrease till the 1990s; after which there was a decline. This time lag between the N inputs to the watershed and the N loads in the river (about two decades) is a function of accumulation of N legacy.
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U2 - 10.1007/s11356-021-16725-x
DO - 10.1007/s11356-021-16725-x
M3 - Article
C2 - 34820757
AN - SCOPUS:85120654202
SN - 0944-1344
VL - 29
SP - 23919
EP - 23935
JO - Environmental Science and Pollution Research
JF - Environmental Science and Pollution Research
IS - 16
ER -