black soil region in Northeast China

black soil in farmland

Black soil in northeast China

Black soil in the farmland

Hg anomalies in soil in urban

Black soil region

black soil region of northeast China

black soil region of the northeast

Northeast black soil region

typical black soil region

Black corn

corn in cold area

corn in dryland

corn in store

Uptake of phosphorus in corn

Weeds in corn field

yellow pigment in corn

two-cropping for wheat and corn in one year

absorbed-hydrocarbons in soil