Nitrogen fate during agricultural managed aquifer recharge: Linking plant response, hydrologic, and geochemical processes.
Sci Total Environ
; 864: 161206, 2023 Mar 15.
Article
en En
| MEDLINE
| ID: mdl-36581286
ABSTRACT
Agricultural managed aquifer recharge (Ag-MAR, on-farm recharge), where farmland is flooded with excess surface water to intentionally recharge groundwater, has received increasing attention by policy makers and researchers in recent years. However, there remain concerns about the potential for Ag-MAR to exacerbate nitrate (NO3-) contamination of groundwater, and additional risks, such as greenhouse gas emissions and crop tolerance to prolonged flooding. Here, we conducted a large-scale, replicated winter groundwater recharge experiment to quantify the effect of Ag-MAR on soil N biogeochemical transformations, potential NO3- leaching to groundwater, soil physico-chemical conditions, and crop yield. The field experiment was conducted in two grapevine vineyards in the Central Valley of California, which were each flooded for 2 weeks and 4 weeks, respectively, with 1.31 and 1.32 m3 m-2 of water. Hydrologic, geochemical, and microbial results indicate that NO3- leaching from the first 1 m of the vadose zone was the dominant N loss pathway during flooding. Based on pore water sample and N2O emission data, denitrification played a lesser role in decreasing NO3- in the root zone but prolonged anoxic conditions resulted in a significant 29 % yield decrease in the 4-week flooded vineyard. The results from this research, combined with data from previous studies, are summarized in a new conceptual model for integrated water-N dynamics under Ag-MAR. The proposed model can be used to determine best Ag-MAR management practices.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Sci Total Environ
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos