The Effect of Salinity of Water Irrigation and Manure on Leaching Escherchia coli in Disturbed Soil Columns

In recent years, microbial contamination of surface and groundwater is a serious problem in some countries, leading to dangerous diseases. Soil salinity and irrigation water can affect the amount of transport or survival of bacteria in soil. In this study, the effect of different levels of salinity of irrigation water with EC: 0.5, 2.5, 6 ds/m and three manures including poultry manure, cow manure and the mixture of poultry and cow manure with 10 ton ha-1 on the transport of Escherchia coli was investigated in disturbed soil columns with 30cm height and 10cm diameter under unsteady-state water conditions. The concentration of Escherchia coli was measured. The severity of the effluent contamination of the treated columns with water salinity was 6 ds/m, which was less than that with the salinity of 2.5 and 0.5 ds/m. This difference was significant at the 0.01 probability level. Also, the effluent contamination of poultry manure-treated columns was greater than the cow manure and the mixed manure, and the contamination of mixed manure was greater than that of cow manure. The interaction of different salinity treatments on the concentration of Escherchia coli in different fertilizer treatments was significant at the 0.01 probability level. The results showed that the concentration of the released bacteria was affected by irrigation water salinity and with increasing the salinity, the concentration of the bacteria was reduced.