The hydro-physical properties of black soil under different type of eco-systems were studied. The results showed that bulk density

SOM

porosity

soil moisture capacity and wet-aggregates run down

when grass eco-system turning crop eco-system. But

fertilizing can restrain the trend

the effect become more significant extra-adding organic manure. Fertilizing promotes planting

especially root growth to improve the hydro-physical properties

moreover

increasing SOM

improving soil structure

adjusting soil moisture capacity and porosity. Bare field eco-system became worse than crop eco-system

confirming plants make important effect to soil hydrophysical properties.