Analysis About Plant Evolution Characteristics And Tests Of Soil Properties On Horqin Sandy Land

This paper regards Horqin sandy land as the studying area,including totally 172 inquired experiments points.The plants condition,the roots growth condition of plants,the humidity condition of soil layer and plant roots are made on-site inspected experiments in the different geography type and different ground condition from June to November in 2002. We carried out the experiments on soil physics and chemistry characteristics and soil nutrient condition by adopting soil samples.As a result, getting the following results:1)Soil of Horqin sandy land mostly belongs to the eclipsed soil,there are the remarkable difference and regulational change about its machine constitutions, the physics and chemistry characteristics in different geography types.2)A different geography of plant evolution is divided into follows:①livings of the sand②the wet living③the wasteland④livings of the salt⑤pasturing⑥natural wood.The primary factors affecting evolution contain weather variety, soil humidity and nutrient, the characteristics of district plant,artificial factors and herd etc,besides mutually competition for the body plants and internal factors for existing. 3)Soil humidity variations for different geography soil in Horqin Sandy sand are affected primarily by soil condition, plant condition,rain,evaporate and deepth in groundwater.In the fixed sand dune and half fixed sand dune in shallow groundwater, there are four districts among the soil from the underground watertable to the soil surface.The total variety trend about soil water content is gradually augment from top to bottom ,in the fixed and the half fixed sand dune,where the groundwater of them is deep.The total variety trend in humidity from surface layer to a depth range (180cm)of research on flowing sand dune augment gradually from surface layer to summit value,then gradually decrease slowly,until reaching a relately dry sand layer, at last increase gradually and get unsaturated variety trend. According to the soil water development on the humidity ground,there are four areas.On the condition of the shallow groundwater the source of soil water are mainly rain and groundwater,however,in sand dune main source of the soil water are rain and condensening water.