煤炭基地村庄压实土壤物理性质变化研究

Study on the Changes of the Physical Properties of the Compacted Soil in Coal Base

土壤压实是影响土地复垦质量的主要障碍,导致了土壤理化性状的改变,难以满足作物生长的要求.结合村庄土壤压实的产生机制,对土路、废弃院落土壤进行采样分析,另取耕作土壤作对比,选取容重、容积含水量、土壤孔隙度、土壤三相比4项指标反映压实土壤物理性质的变化.结果表明：压实导致土路表层容重高达1.75 g/cm3,院落表层土壤容重接近1.60 g/cm3,高于土壤耕作层容重1.40 g/cm3；在土壤深度不超过70 cm时,土壤容积含水量高低依次为耕地、土路、院落,土壤深度超过70 cm时,无明显变化规律；对土路、院落土壤的压实导致土壤孔隙度由适宜作物生长的45％～50％减小为35％～45％；土路、废弃院落、耕作土壤三相比依次为6：3：1,6∶ 2∶2,5∶3∶2,压实导致土壤固相体积增大,大空隙减少、小空隙被水封闭、透气性减弱,土壤保水能力减弱.

Soil compaction is the main obstacle that affects the quality of the land reclamation, leading to changes of soil physical and chemical properties, so it is difficult to meet the requirements of crop growth. Com- bined with the generation mechanism of soil compaction, a sampling analysis of embankment and courtyard soils was carried out compared with cultivated land, the bulk density, bulk density water content, soil porosity and the rate of soil phases were selected as the four indexes which indicated the physical properties of compac- ted soil. The results showed that compaction caused the high bulk density of the surface of soil embankment, making 1.75 g/cm3 , and that of the surface of soil courtyard close to 1.60 g/cm3 , higher than that of cultivat- ed layer 1.40 g/cm3 ; which was at the soil depth no more than 70 cm, the order of the soil bulk density water contents was cultivated land 〉 soil embankment 〉 courtyard, at the soil depth more than 70 cm, no definite trend was observed ;compaction of soil embankment and courtyard reduced the soil porosity from 45% -50%, which suits corp growth, to 35% -45% ;the rates of soil phases of soil embankment, courtyard and cultivated land were in the sequence of 6： 3： 1,6： 2： 2,5：3：2, compaction reduced big porosities, closed small porosities by water, decreased permeability hence the decrease of water retaining capacity of courtyard soil.