According to mass balance model and the assumption that before 137Cs in plow layer was mixed for a uniform distribution

the surface of cultivated soil would form a surface enrichment layer

a quantitative model was developed to relate the amount of 137Cs enrichment from the cultivated soil profile to soil deposition rate.During the construction of the model

the depth of surface enrichment layer

the 137Cs depth distribution pattern in enrichment layer

the 137Cs decay constant

the 137Cs input fraction

the depth of plow layer

and sampling year were considered.Results from the model construction prove that the relationship between the rate of soil deposition and 137Cs enrichment is neither linear nor logarithmic.