Study On Wind Erosion Characteristics Of Cultivated Land In Potato Sprinkler Irrigation Circle In Sandy Land

Potato sprinkler irrigation circle farmland lacks protective farming measures such as stubble and no-tillage,and becomes a source of wind and sand during the wind season.Wind erosion not only causes soil desertification and nutrient loss of farmland,but also wind-eroded sand substances will have a serious impact on the surrounding environment.Round-faced arable land and deep plowing harvesting are the basic characteristics of potato sprinkler irrigation circle arable land,which also causes the existence of certain peculiarities in the law of soil wind erosion.This thesis selects the potato sprinkler irrigation circle farmland in the sandy land of the northeastern edge of the Kubuqi Desert as the research object,and compares it with the uncultivated fixed sandy land around it.Observation of indicators such as diameter and other indicators in the field can reveal the characteristics of soil wind erosion in the potato sprinkler irrigation circle farmland in sandy areas,and provide a theoretical basis for the prevention and control of soil wind erosion in sandy areas.The main research conclusions are as follows:（1）There is serious wind erosion in the potato sprinkler irrigation circle,and the wind erosion amount is 504t·hm^-2 in the wind season.Compared with the control,the amount of sediment transport increased by 103.35 times,and the content of clay and silt particles in the sand material output to the cultivated land increased by 3.52 and 4.97times,respectively.（2）Different lengths of aeolian sand transport paths have a significant effect on sand material transport.When the surface creep and saltation sediment material moves along the path,its content shows a trend of first increasing,then decreasing and then increasing.Overall,the activity is stable in the upwind and downwind parts of the circular surface cultivated land,while the activity is intense in the middle-wind parts.When the aeolian sand flow moved from upwind to downwind along the path,the aeolian sand flow unde r each path was enhanced,and the sediment transport increased by 51.97 times compared with the upwind,and the content of clay particles and silts in the 100-200cm height increased by 81.73%on average.（3）After harvesting and before spring ploughing the following year,the cultivated land was affected by wind and sand,and the undulating micro-topography produced by harvesting evolved into flat terrain,and the surface roughness decreased by 91.01%;affected by the movement of wind and sand,the undulating high point of the micro-topography the average drop was 9.13cm,and the low point of the ups and downs rose by an average of 3.84cm.In the process of micro-topography changes,the aerodynamic roughness and friction velocity are both decreasing.When t he undulating topography is significant,the structure of the transit wind-sand flow changes significantly,and the amount of sediment transport shows a trend of decreasing fluctuation with height.The structure of the wind-sand flow is characteristic the value is between 2.73 and 3.60.The upper layer of the sand flow accounts for a relatively large proportion of the sand flow,and the wind erosion base level rises;when the terrain is leveled,the structure of the wind sand flow across the border does not change,and the sand flow shows a monotonous decreasing trend with height.The characteristic value of the wind-sand flow structure is between 1.14 and 1.39,and the amount of sand transported in the upper and lower layers of the wind-sand flow is gradually approaching,and it begins to tend to a state of equilibrium.（4）Aeolian sand caused a large amount of fine particle loss in the surface soil of cultivated land,resulting in the decrease of the average soil particle size,the development of sorting to medium,skewness to extremely positive,kurtosis to narrow,and the decrease of fractal dimension.The contents of clay,silt and fine sand decreased by 42.14%,48.85%and 42.28%,respectively.Compared with the control group,the average particle size of soil decreased,the sorting ability became worse,and the skewness had no significant difference.The kurts narrowed to the extreme tip,and the contents of clay,silt,fine sand and medium sand decreased by 65.10%,69.60%,56.45%and 18.06%,respectively.