Investigation of some chemical properties and amounts of some nutrient elements associated with dust in Sistan Plain

Land degradation is one of the major threats to ecosystems, especially in arid areas due to drought and wind erosion. Dust characteristics can indicate the extent of land degradation. The aim of this study is an assessment of some chemical characteristics and amounts of some nutrient elements of dust in the Sistan Plain. Twenty-five half-spindle shaped dust samplers were installed in the cities of the Sistan region. The dust samples were collected monthly from early April until late September in 2015. Topsoil samples from erodible or susceptible areas to erosion were taken (20 samples) from different parts of Hamoun wetlands (as the main origin of dust). After that pH, EC, organic matter, soil texture, and amount of soil nutrient elements including P, K, Na, Ca, and Mg were analyzed in samples. The Ca was the maximum nutrient elements associated with dust (average 700.28 mg/kg), and the minimum was P (average 33.76 mg/kg). The highest amount of Total (P, K, Ca, Mg and Na) nutrient elements were observed in August+September (461.43 mg/kg) and the minimum amount in May+June (353.78 mg/kg). The highest amount of OM, P, K, and Mg have observed in dust loaded over Zabol city (25.88 mg/kg, 45.75 mg/kg, 365.8 mg/kg and 667.32 mg/kg respectively), and the maximum amount of Ca was observed in Hamoun city (813.06 mg/kg) and the maximum amount of Ca was observed in Nimruz city (629.48 mg/kg). The highest amount of enrichment ratio belonged to P (6.002) and the lowest enrichment ratio belonged to Na (0.707). The results showed soil textures of Hamoun wetland beds are susceptible to erosion and its chemical properties showed salinization and alkalization and loss of vegetation cover. Characteristics of the dust carried over the cities of Sistan plain reflected the conditions of dust origin and indicated the expansion of land degradation in these areas