Experimental Research On The Effect Of Straw Mixture On Soil Water And Salt Transport

The northwestern region is arid and rainless,the soil is barren,and the evaporation is extremely high.The special geographical location and climatic conditions have formed a large amount of saline soil.Due to lack of water resources,ecological restoration costs are higher and restoration is more difficult.It is very important to choose a suitable ecological restoration method.Therefore,in this study,wheat straw was selected as the soil improvement material,and the soil of the Hongshaquan coal mine dump in Zhundong,Xinjiang was taken as the research object,and the mixing amount and crushing degree of the straw were set as influencing factors.Systematic study of the movement law of soil water and salt under different straw treatments,in order to improve the soil texture,improve the desertification and salinization of the mining area,and achieve the purpose of ecological restoration.The main research results are as follows:(1)Under the one-dimensional water infiltration experimental treatment,different straw treatments reduced the soil infiltration performance,and the soil infiltration capacity was related to the mixing amount and crushing degree of the straw.When the mixing amount of straw is 1%and 2%,the infiltration capacity is shown as powdery>1cm>5cm;when the mixing amount of straw is 3%,the infiltration ability is shown as powdery>5cm>1cm.When the straw is in powder form,the infiltration capacity is expressed as mixing amount 1%>mixing amount 3%>mixing amount 2%;when the degree of pulverization is 1cm,the infiltration ability has a negative relationship with the straw mixing amount.The mixing amount is 1%>the mixing amount is 2%>the mixing amount is 3%;when the degree of pulverization is 5cm,the infiltration capacity is shown as pure soil>mixing amount 3%>mixing amount1%>mixing amount 2%.(2)The power function can fit the relationship between the distance and time of the wetting front under different straw treatments,and the correlation coefficient R~2 is between 0.9922-0.9987.The Kostiakov infiltration model can accurately reflect the change law of soil moisture accumulation and infiltration under different straw treatments,and the correlation coefficient R~2 is between 0.9925-0.9991.The distance between the advancement of the wet front and the cumulative infiltration under different straw treatments is in a linear relationship,and the correlation coefficient R~2 is between(0.9937-0.9994).(3)Mixing wheat straw at 0-15 cm of soil can inhibit soil water evaporation,but there is no significant difference between different treatments.The cumulative soil evaporation performance is pure soil>powder(mixing amount 1%)>1cm(mixing amount 1%)>powder(mixing amount 3%)>1cm(mixing amount 3%).Soil water evaporation inhibition is manifested as mixing amount 3%>mixing amount 1%,segmented straw>powdered straw,and evaporation inhibition is related to mixing amount,the higher the mixing amount,the difference between different pulverization degrees Bigger.The evaporation inhibition rate of powdered straw decreased slightly with the increase of time,while the evaporation inhibition rate of segmented straw increased continuously with time.(4)Black evaporation model and Rose evaporation model can well simulate the relationship between soil moisture cumulative evaporation and time under different straw treatments,and the correlation coefficient R~2 is between 0.961-0.998,which has a strong correlation.The correlation coefficient of the Rose evaporation model is larger than that of the Black evaporation model,and it can more accurately reflect the influence of straw mixing on the cumulative evaporation of soil water.(5)Straw mixing improves the water holding capacity of the upper layer of the soil.The water holding capacity is segmented straw>powdered straw,and the mixing amount is 3%>the mixing amount is 1%.In the evaporation stage,the straw blending increases the evaporation of surface soil moisture and inhibits the evaporation of the lower soil moisture.After the straw blending,the surface water storage capacity increases,and the water retention capacity is 1cm(mixing amount 3%)>powder(Mixing amount 3%)>1cm(mixing amount 1%)>powder(mixing amount 1%)>pure soil.(6)Mixing straw in the soil effectively inhibits the surface accumulation of soil salt,and has a leaching effect on the soil salt during the infiltration process,and has a certain desalination effect on the upper soil.The salt leaching effect is powdery(mixing amount 3%)>1cm(mixing amount 3%)>1cm(mixing amount 1%)>powder(mixing amount 1%)>pure soil.After the 21-day evaporation experiment was over,the soil profile salt distribution changed from"\"to"Z"shape,powdered(mixed amount 1%),powdered(mixed amount 3%),1cm(mixed amount 1%)),1cm(mixing amount 3%),the average salt content of 0-20cm soil is reduced by 7.98%,13.50%,9.36%,14.42%compared with pure soil,and the salt control effect is shown as mixing 3%>mixing1.%,segmented straw>powdered straw.This shows that mixing straw in the soil can effectively reduce the salt content of the cultivated soil,which is of great significance for improving the saline soil and plant growth.(7)Combining force control configuration software with soil sensors to study the law of soil moisture change is an effective research method.The process of the experiment reflects the change process of soil moisture in more detail,increasing the number and avoiding the impact on the soil structure.Destruction helps to discover new laws of change in research and provides new methods for mechanism research.The current system uses limited monitoring.In future field studies,the system can be upgraded and the network can be used to carry out remote monitoring,which can minimize the workload and research costs.