The Three-North Shelter Forest Program (TNSFP) has played an important role in increasing the forest coverage
and decreasing the wind erosion rate. Fallout radionuclides (FRNs), such as caesium-137 (137Cs) and excess lead-
210 (210Pbex), have extensively been used as fast and economical tools to estimate erosion rates over a broad
range of spatial and temporal scales. However, the 137Cs and 210Pbex conversion models used to estimate annual
soil erosion rates under steady state conditions have not been used to predict corresponding rates following
reforestation due to the land-use changes that have occurred since 1963 in China. This study investigated the
influence of shelter forest on soil erosion of cultivated land (CL) by using 137Cs and 210Pbex in northern China.
Opposing trends in the spatial variation were found between the 137Cs and 210Pbex inventories, which were due to
their differing sources and mass balances within the soil profile. Exploiting this finding, we propose a conceptual
137Cs and 210Pbex variation model to detect depth variations between before and after reforestation. Wind erosion
rate was 29.11 ± 14.42 Mg ha-1 yr-1 in the CL when estimated with 137Cs. However, estimation by the revised
210Pbex mass balance model showed that wind erosion rates were 68.55 ± 22.11 and -8.52 ± 47.32 Mg ha-1 yr-1
before and after the surrounding forest matured, respectively. The spatial variation in the 137Cs inventories
mainly reflects the soil erosion patterns before the surrounding shelter forest matured, while the spatial variation
in the 210Pbex inventories mainly reflects the soil erosion patterns after the surrounding shelter forest matured.
Furthermore, the soil erosion rates that were deduced from the 210Pbex conversion model confirmed that the
TNSFP played an important role in decreasing the soil erosion rates and intercepting sandstorms in northern
China. Thus, the advantages and limitations associated with the use of FRNs for assessing wind erosion in the
study area were also proposed. More attention should also be paid to the limitation of estimating soil erosion
rates by using FRNs measurements in the TNSFP region of China.