אסיף מאגר המחקר החקלאי

Nitrate fluxes to groundwater under citrus orchards in a Mediterranean climate: Observations, calibrated models, simulations and agro-hydrological conclusions

Year:

2013

Source of publication :

Authors :

Volume :

151

Co-Authors:

Kurtzman, D., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel
Shapira, R.H., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel, Hydrology and Water Resources Studies, Hebrew University of Jerusalem, Israel
Bar-Tal, A., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel
Fine, P., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel
Russo, D., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel

Facilitators :

Link :

Abstract:

Nitrate contamination of groundwater under land used for intensive-agriculture is probably the most worrisome agro-hydrological sustainability problem worldwide. Vadose-zone samples from 0 to 9 m depth under citrus orchards overlying an unconfined aquifer were analyzed for variables controlling water flow and the fate and transport of nitrogen fertilizers. Steady-state estimates of water and NO3-N fluxes to groundwater were found to vary spatially in the ranges of 90-330 mm yr- 1 and 50-220 kg ha- 1 yr- 1, respectively. Calibration of transient models to two selected vadose-zone profiles required limiting the concentration of NO3-N in the solution that is taken up by the roots to 30 mg L- 1. Results of an independent lysimeter experiment showed a similar nitrogen-uptake regime. Simulations of past conditions revealed a significant correlation between NO3-N flux to groundwater and the previous year's precipitation. Simulations of different nitrogen-application rates showed that using half of the nitrogen fertilizer added to the irrigation water by farmers would reduce average NO3-N flux to groundwater by 70%, decrease root nitrogen uptake by 20% and reduce the average pore water NO3-N concentration in the deep vadose zone to below the Israeli drinking water standard; hence this rate of nitrogen application was found to be agro-hydrologically sustainable. Beyond the investigation of nitrate fluxes to groundwater under citrus orchards and the interesting case-study aspects, this work demonstrates a methodology that enables skillful decisions concerning joint sustainability of both the water resource and agricultural production in a common environmental setting. © 2013 Elsevier B.V.

Note:

Related Files :

Related Content

More details

You may also be interested in