Abstract:
Northeastern black soil area is one of important regions for crop production and commodity grains in China,which takes the key role in stabilizing national grain markets and keeping national food security.The long term cultivation with less soil conservation has caused serious soil erosion and threatened food production in this area.This paper focused on the black soil region in SonghuajiangNenjiang plain,which is about 20.8 million hm
2,and estimated soil loss from the cultivated land by using 950 point survey data and soil loss data measured from plots and
137 Cs.The cultivated land is about 17.274 million hm
2 in the study area.The soil loss prediction equation for crop land is A =0.737 9
θ.The analysis result showed that the study area has rolling hill topography by using SRTM elevation data with resolution of 90 m×90 m.The percentage is 72.25% of the total area for slope steepness less than 1°,27.05% for slop ranges of 1°-5°,and only 0.70% for slope steeper than 5°.But the large slope length caused serious soil erosion for the crop land.Soil loss calculated from both plot and
137 Cs measured data showed that the area of soil erosion is about 13.394 9 million hm
2,which is 64.40% of the study area and 77.54% of the crop land in the study region.It is urgent to take practices for soil conservation.In addition,to understand the soil loss rate for the northeastern China,it is necessary to strengthen the soil loss monitoring and soil erosion research.