Rates in a Cultivated Land in Iran

3 Abstract: Soil erosion is the most important soil degradation process in Iran's agricultural lands. However, only limited data are available on the actual magnitude of soil erosion. The study area was a dry farming land located in Koohin, Qazvin province, Iran. Cs measurements were undertaken on 44 soil samples collected within a 137 seven hectares cultivated field were used to determine the magnitude and spatial pattern of medium-term soil redistribution budgets. The mean erosion and deposition rates were estimated to be 14.2 and 11.1t ha yr 11 respectively using Mass Balance Model 2. The Mass Balance Model 3 was applied to highlight the contribution of tillage effect in soil redistribution. The results showed that the contribution of tillage on soil redistribution during last 50 years was not negligible. However, water erosion is the main process which influences the soil removal from the field, while tillage erosion acts as a translocation process within the field. The net soil loss reached 4.6t ha yr which was relatively higher than the results of erosion plots in the study area. 11