Taking the Nihegou small watershed in Chunhua county as an study object

through testing the soil samples in different times and data statistics from the small runoff region

it was known that there was a clear space distribution law of the soil nutrients variation in the region. Mostly because of water and soil loss the soil fertility became declining from watershed to the edge of gully

and the area was enlarging from gully valley to riverbed. Therefore it is the effective way to protection and recovery soil fertility through comprehensive controlling soil erosion and mulching with film and interplanting in the sloping farmland.