An alternative method to treat the nitrate-contaminated groundwater under the agricultural fields while providing economic benefit is called pump and fertilize. Pump and fertilize, while removing the nitrate in the groundwater, can reduce nitrate and pesticide requirement. However, up to date, there are no studies evaluating the effect of this application under different soil/climate conditions. In order to apply this technology in the field and to determine its effect, a feasibility study needs to be performed. Therefore, we constructed unsaturated zone groundwater models via HYDRUS 1D for one-hectare corn field in prevalent soils and under Eskişehir, Adana, Şanlıurfa, Düzce climates in Turkey. Our results indicated that even groundwater with 50 mg/L nitrate contamination could provide economic benefit to the agriculture especially where climates and soil types are similar to Şanlıurfa. In this climate using pump and fertilize technique saves 97 kg N/year in a 1-hectare farm. The technique was especially effective for fluvisol, vertisol soils as nitrate leaching are very low, and for cambisol soils since very high nitrogen use efficiency was seen for the climates present in Turkey. Our results indicated that in general the pump and treat efficiency is less effective in wet and cold climates, like in Düzce. As a general result of our study, we concluded that dry and warm climates with relatively permeable soils are more promising for the pump and fertilize application.

Identification of the current and expected future pollution sources to rivers is crucial for sound environmental management. For this purpose numerous approaches were proposed that can be clustered under physical based models, stable isotope analysis and mixing methods, mass balance methods, time series analysis, land cover analysis, and spatial statistics. Another extremely common method is Principal Component Analysis, as well as its modifications, such as Absolute Principal Component Score. they have been applied to the source identification problems for nitrogen entry to rivers. This manuscript is checking whether PCA can really be a powerful method to uncover nitrogen pollution sources considering its theoretical background and assumptions. Moreover, slightly similar techniques, Independent Component Analysis and Factor Analysis will also be considered.