Effect of municipal sewage effluent on soil and crops cultivated on a hyper-arid zone sandy soil

The effects of sewage effluent from Sebha Municipal Area in the Fezzan region of Libya on certain physicochemical properties of a hyper-arid zone sandy soil and growth of two plants were studied. The soil had been treated daily with 25, 50, 75 and 100% effluent; and barley (Hordeum vulgare) and broad beans (Vicia faba) had been grown on the soils in pots. Soil samples were analysed for water-soluble salts, electrical conductivity, cation exchange capacity, pH, organic matter, sodium, potassium and phosphorus. At all the concentrations of effluent used there was a significant increase in all the soil properties tested. The greatest changes were observed with 100% effluent. The soils supporting crops were found to have lower concentrations of nutrients than those without crops. There was an increase in dry matter production by plants grown in effluent treated soils. The results indicate that sewage effluent could be considered as one of the possible and alternate sources of irrigation water.