Investigation of Nitrate Contamination in Groundwater, Soil, and Crops (Case Study: Fasa Plain)

Nitrate contamination in groundwater resources and crops is increasing due to human activities and urban development. This study has aimed to investigate on nitrate contamination in groundwater, soil, and some crops of Fasa plain.

After sampling of groundwater, soil, and some crops, the nitrate content and the other quality parameters were measured. T-tests and a data correlation test were performed using SPSS and Excell software to investigate on nitrate contamination and its origin. Spatial zoning of nitrate also performed using ArcGIS.

The statistical test indicated the presence of nitrate contamination in the groundwater of the region; however, the soil did not show nitrate contamination in the area. Nitrate level in four types of crops, lettuce, beans, onions, and spinach, was within the allowable range, and in beans, it is close to the allowable limit. At the same time, among the leafy plants, the concentration of nitrate in lettuce was higher than in spinach, and it was lower in onions than in the others.

The lack of significant correlation between nitrate ions and the other ions of lithological origin suggests the anthropogenic origin of nitrate in the groundwater in the region. The high ratio of nitrate to chloride also indicates the significant impact of chemical fertilizers and the less important role of domestic wastewater, especially in the outlet of the plain. The amount of nitrate in some of the studied crops is close to the permissible level, shows the need to pay attention to their consumption and continuous monitoring of water, soil, and plants in terms of the pollution.