In Neretva valley agricultural production is very intensive. Due to the dry summer irrigation is necessary. However, agricultural measures, intrusion of the sea, and precipitation have a major impact on the quality of the water for irrigation. This thesis describes a part of a research in the area Lower Neretva Valley - location Vrbovci, where over the three years (2011, 2012 and 2013) in four different microlocations data on physical and chemical parameters of the quality of water for irrigation were gathered, such as: electrical conductivity, and nutrients - nitrate, ammonium, potassium and phosphorus. Descriptive and biometric analysis were carried out for the purpose of comparison of the average of microlocations and years of research for each studied variable (variance analysis), as well as an assessment of the correlation of variables for each research year and the total for all years in each microlocation (correlation). Trends in terms of the studied variables on four microlocations and research period is further graphically depicted. Results of variance analysis for the difference between the years of research on the individual microlocation demonstrate that the significant difference in EC, NO3- and K+ appears only on the microlocation of Vrbovci P. The variable NH4+ has no significant difference in any microlocation, while the variable P shows significant difference in microlocations Lateral channel and Vrbovci channel. Results of variance analysis for the difference between microlocations in each year of the research show that each year significant differences between the four studied locations for variables EC, NO3- and K+ occurs. The variable NH4+ has no significant features on the tested micro-locations. The variable P has no significant features in 2011, while 2012 and 2013 shows significant features. Results show a correlation relationship of all the variables in all the studied years on a single microlocation, the Lateral channel. Looking at the correlation of the related variables studied from 2011 to 2013, a significant association is demonstrated at micro-location CS Kosevo between the variables EC and NO3-, EC and K+, NO3- and K+, at Vrbovci channel between all variables, and at Vrbovci P between variables EC and K+, NO3- and K+, NH4+ and K+, and K+ and P.