Effects of nano iron oxide powder and urban solid waste compost coated sulfur on chemical properties of a saline-sodic soil

The main limiting factors in saline-sodic soils are high amounts of salts, low soil organic matter (som) and low availability of macro and micro-nutrients. the effect of different amounts of nano iron oxide powder and urban solid waste compost coated sulfur (uswcs) on the chemical properties of a saline-sodic soil was investigated. the experiment was conducted using a randomized complete block design with factorial arrangement and three replications, in a farm near qom city. treatments used in this study included uswcs (0 and 15 ton/ha) and nano iron oxide powder (0 and 20 mg/kg); treatments were applied to treated plots of 4 m2 and sunflower seeds were sown. the results show that 20 mg/kg of nano-iron oxide, significantly (p<0.05) increased electrical conductivity of saturation extract (ece), availability of nutrient elements (5.26, 30, 18.18% for phosphorous (p), iron (fe), and copper (cu), respectively) in soil, while nitrogen (n), ph and sodium adsorption ratio (sar) in soil decreased significantly (p < 0.05). fifteen (15) tons/ha of uswcs significantly increased soil ece (6.1%), micro and macro-nutrients amounts (8.3, 21.1, 46.6, 45. 5, and 14.9% for n, p, fe, cu, and manganese (mn) respectively), but significantly (p < 005) decreased the soil ph and sar, compared to the control. the combined effect of 20 mg/kg of nano iron oxide and 15 ton/ha of uswcs increased micro-nutrient availability, but decreased soil ph and sar significantly. it was concluded that the combined application of uswcs and nano iron oxide increased the availability of nutrients in saline-sodic soil.