摘要：The water of many rivers all over the world is used for irrigation purposes. Maritsa River, located in the Thracian Valley, Balkan Peninsula, on the territory of Bulgaria, Turkey and Greece, is one of them. Apart the water quantity, the performance of irrigated agriculture depends also on its quality. In the present study, the quality of Maritsa River water as a source for irrigation was assessed at two monitoring points (MPs) in Bulgaria - MP-1 (upper river) and MP-2 (middle course of the river). The samples were taken in June and August 2014 and 31 physicochemical and microbiological parameters were screened. Water sampling and preparation were performed according to Bulgarian standard complied with ISO standards. Physicochemical parameters were determined spectrophotometricaly, by Multi/340i SET and AAS. For the estimation of total and specific microbial load, selective chromogenic culture medium sheets were used. It was found that river water quality meets the requirements of Bulgarian standard for irrigation water with respect to: temperature, pH, electrical conductivity, total hardness, Ca, Mg, dissolved oxygen, BOD5, COD, N-NH4 (except for June), N-NO3, Cl-, SO42-, P-PO4 (except for August), suspended solids (except for June), Mn, Fe, Cu, Zn, Pb, Ni, Cd, Cr and As. Deviations from the standard were observed for all microbiological parameters at both MPs. The metal concentrations decrease in the order of Fe>Zn>Ni>Pb>Cr>Cu>As>Mn>Cd. Many significant correlations were revealed between controlled water parameters.
