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Nitro-pollution in a confined aquifer may originate from its recharge area, e.g., agricultural sites, animal feedlots, septic tanks, and other waste disposal sites or from treated wastewater recharge wells. The latter case is studied. Existing water supply pumping wells should be protected for a given period. Instead of typically investigating optimal pump-and-treat or hydrodynamic pollution control management/remediation strategies, a novel combined pollution control and pump-and-fertilize (PAF) approach is proposed: protect existing wells with additional wells, considering pumped nitro-polluted groundwater as profitable reusable fertilizer rather than a pollutant to be remediated; convey pumped polluted water to an irrigation reservoir, considering nitrogen (N) uptake by irrigated crops in nearby farmlands and proportional decrease in fertilizer application, meaning profit. Optimization entails the operation of optimally located additional pumping wells with optimal flow rates, minimizing the sum of (i) annual pumping cost, (ii) pipe network (connecting additional wells and reservoir) amortization cost, and (iii) profit from retrieved N reuse. Modflow simulates a 3D flow field and advection-dispersion mass transport, while Genetic Algorithms (GAs) handle optimization. Various scenarios are simulated concerning crops' retrieved N root uptake percentage, fertilizer, and energy market prices. The paper provides a data-ready optimization/decision support tool that creates a pool of alternative (sub)optimal management solutions/strategies. [ABSTRACT FROM AUTHOR]

Due to the sensitivity of kiwifruit to soil water and nutrient availability, kiwi production is often associated with over-watering and over-fertilization, especially with nitrogen (N), resulting in increased environmental risks. Crop models are powerful tools for simulating crop production and environmental impact of given management practices. In this study, the CropSyst model was applied to estimate soil N budget and environmental effects of kiwi production, with particular regard to N losses, in two grower-managed kiwi orchards in northern Greece, involving two seasons and different management practices. Management options included N fertilization and irrigation. Model estimates were compared with yield and soil mineral N content (0–90 cm depths) measured three times within the growing season. Agri-environmental indicators were calculated based on the N budget simulation results to assess the environmental consequences (focusing on N losses and water use efficiency) of the different management practices in kiwi production. According to model simulation results, kiwifruit yield and N uptake were similar in both orchards. N losses to the environment, however, were estimated on average to be 10.3% higher in the orchard with the higher inputs of irrigation water and N fertilizer. The orchard with the lower inputs showed better water and N use efficiency. N leaching losses were estimated to be higher than 70% of total available soil N in both study sites, indicating potential impact on groundwater quality. These findings demonstrate the necessity for improved irrigation and N fertilization management in kiwi production in the area. [ABSTRACT FROM AUTHOR]