Spatial distribution of total phosphorus and organic carbon in the salt-affected soils in the Meyghan Playa, Iran

Due to widespread and fast-growing urban developments, large amounts of industrial, agricultural, and municipal wastewaters are produced which can change ecosystem functions after being released into rivers and lakes. The distributions of organic carbon (OC) and total phosphorus (TP) of soil were studied in the salt affected soils in the Meyghan Playa, Iran, to show the impacts of human activities on these soils and sediment properties in this arid region of the world. Samples were taken from 250 points and were analyzed geostatistically for electrical conductivity (EC), pH, TP, and OC. Although EC had the highest coefficient of variation (CV = 2.4) compared to CVs of the other soil properties, the sill/nugget ratio for EC in the geostatistical analysis was the highest one. Therefore, EC had the strongest spatial dependence compared to OC, TP, and pH with lower sill/nugget ratios and moderate spatial dependence. The maximum amount of OC was more than 2% which was observed near the entrance of municipal wastewater to the Meyghan Lake, and the highest soil TP was more than 400 kg mg-1 near the entrance of municipal wastewater and also at river mouths, which can be attributed to leaching and runoff fertilizers from farmlands. Enrichment of OC in the entrance of municipal wastewater toward the lake is related to eutrophication and higher plant production.