Groundwater Quality Dynamics from Field Experiments on Watershed Level in Southern Bulgaria

The results of the groundwater dynamics are presented realized on the territory of a small watershed at the experimental station Tsalapitsa in South Bulgaria, under Fluvisol. The shallow waters of three permanent built wells from the experimental field were studied when growing different crops with different fertilization for the period 2016-2018. The samples for chemical analysis were taken monthly. It was found that different agricultural practices influenced significantly on the content and dynamics on nitrogen in the shallow groundwater. The highest concentration of nitrogen were measured when vegetables were grown, while at a change in the loading with fertilizers the values are lower around and below MPCL The calcium concentrations of groundwater vary in considerably short range, such as correlates to a certain extent with the nitrate content.