Relationships of 137Cs inventory with magnetic measures of calcareous soils of hilly region in Iran

Erosion is a natural process, but it has been dramatically increased by human activities; and this adversely influences soil productivity and environmental quality. For quantification of soil erosion, several techniques including the use of Cs-137 have been employed. This study was conducted to explore the relationships of Cs-137 inventory with magnetic properties in calcareous soils in western Iran. Ten transects were selected in the hilly region in Chelgerd district of Iran. Soil samples from 0 to 30 and 30–50 cm depths were collected from fifty points to determine Cs-137 inventory, magnetic measures and selected physico-chemical properties (in total there were 100 soil samples). The results showed that simple mass balance model (SMBM) estimated a gross erosion rate of 29.6 t ha−1 yr−1 and a net soil deposition of 21.8 t ha−1 yr−1; hence, a net soil loss of 9.6 t ha−1 yr−1 and a sediment delivery ratio of 31.4%. Simple linear regression and non-linear regression analysis showed that mass magnetic susceptibility (χlf) explained only 33.64% and 45% of variability in Cs-137 in the transects studied. The results of multiple linear regression analysis of 137Cs with magnetic parameters and physico-chemical properties indicated that extractable potassium and χlf explained approximately 61% of the total variability in 137Cs in the area studied. Overall, the results suggest that further research is needed for the use of magnetic characteristics as an alternative technique in place Cs-137 methodology for calcareous soils. - Highlights: ► Simple linear regression mass magnetic susceptibility (χL) explained only 33.64 % of Cs-137 variability. ► Non-linear regression model explained 45% of variability in Cs-137 in the transects studied. ► Magnetic Susceptibility measures could not directly be used in calcareous soils to evaluate soil redistribution. ► Magnetic characteristics as an alternative technique instead of Cs-137 in calcareous soils should be further investigated.