Study On The Soil Physical-chemical Characteristics Of Different Farmland Types And The Path Analysis In Yellow River Flood Area By The Case Of Lankao

Cultivated land is an important component of land resources,and the influence of human activities is very strong,which is related to the survival and development of mankind.It is the foundation for the steady development of the society.Because of the long period of break and change,the yellow pan has formed a variety of microgeomorphic forms and developed the corresponding cultivated land types.Although scholars have carried out many researches on soil physical and chemical characteristics and wind erosion characteristics in the yellow pan area,however,the research on specific cultivated land types under the influence of microgeomorphology is not enough.Therefore,this article has used the method of combining the field investigation and indoor test to analyzes the different types of cultivated soils in physical and chemical properties and the difference of the cultivated land wind erosion characteristics of impact factor with the help of a EXCLE and SPSS 19.0,and we have reashed the following conclusions:(1)The soil particle composition and fractal dimension of different cultivated land types were significantly different.The fractal dimension,clay content and silt content were the highest in the flat farmland,followed by the beach land,and the lowest in the sandy land.This indicates that the coarse grained degree of soil particle composition(soil texture)is that sand hillock farmland were higher than flat farmland and beach farmland.In vertical direction,the fractal dimension of soil in different cultivated land types was significantly different,and the difference of soil layer size was inconsistent.The fractal dimension of soil in 0-l0cm soil layer was the biggest difference,and the fractal dimension decreased with the increase of soil depth,and the sand soil cultivated land slowed down fastest.The results showed that the soil coarse degree of soil mechanical composition in different types of cultivated land had the largest difference in 0-l0cm,and the coarse grained degree of soil texture increased with the increase of depth,and the coarse granulation of sand hillock farmland was the fastest.(2)The difference of soil moisture in different cultivated land types is significant.From the river near the water content is higher,the moisture content of different soil types is the largest in the beach farmland and the cultivated land is the lowest,different soil depth soil moisture content significantly,the biggest difference is the 0-10cm layer,soil water content increased with the increase of soil depth,and the change of Sha Gang the largest cultivated land.The results showed that the water holding capacity and storage capacity of soil in 0-l0cm layer were the biggest difference,and the capacity of sand hillock farmland was the worst.among different types of cultivated land.(3)Soil bulk density and porosity difference of different cultivated land types are significant,and the soil density and loose degree of sand hill farmland are the largest.The total porosity,capillary porosity and water retention are the opposite of soil weight.Soil bulk density and porosity are significantly different in different soil layers,which are more specific to the depth of soil.The density of soil is increasing,the porosity is decreasing and the soil is becoming more and more compactness(4)There are significant differences in the porosity of non-capillary tubes in different cultivated land types,the maximum of soil permeability and air permeability is in sand hill farmland,and the second is flat farmland,and the least is beach land.The porosity of non-capillary tube in different soil depth is significant,and the permeability of the non-capillary tube is decreased with increasing depth.(5)Soil chemical properties of different cultivated land types were significantly different,but their nutrient contents were different.Soil nutrient conditions between different land types,soil organic matter,alkali solution nitrogen,rapidly-available potassium,total phosphorus,effective phosphorus)were characterized by silt ground of cultivated land is best,the quay cultivated land,sand hills of cultivated land is the worst.Different soil depth,except the total phosphorus,other nutrient content difference was significant,as the soil depth increased,the soil nutrient content decreased gradually,but different nutrient decrease rate is different;Different types of cultivated land is the most easy to loss of nutrients,sand hills of arable land,organic matter,alkali-hydro nitrogen,rapidly-available potassium loss,fastest fastest silt ground of cultivated land loss of total phosphorus,the quay fastest cultivated land effective phosphorus loss.(6)The fractal dimension is positively correlated with the viscosity,particle size,total porosity and capillary porosity,which is negatively correlated with the content of bulk density and sand grain.The rational correlation between organic matter and water cultural relic is obvious,which is positively correlated with total porosity,capillary porosity,granule and clay,and is negatively correlated with tolerance and sand content.Organic matter and other nutrient elements are also correlated,with the rapid effect potassium,hydrolysis nitrogen,total phosphorus and effective phosphorus.(7)The main factors affecting the erosion of cultivated land in lankao county of huangpan district are the accumulation time of wind speed,crop cover and roughness.The wind speed accumulation time in the direct influence factors is the largest,the roughness is the second,the crop coverage is the smallest;The roughness in the indirect influence factors is the largest,the crop cover is second,the wind speed accumulates the time;Determinant role to wind erosion amount is the wind speed accumulation time>wind speed accumulation time and crop coverage>wind speed accumulation time and roughness>crop coverage and roughness>crop coverage>roughness.(8)The direct path coefficient of wind speed accumulation time and crop coverage is large,and the indirect path coefficient is small,mainly through the direct impact on wind erosion.The direct path coefficient of roughness is small,and the indirect path coefficient is large,which mainly reduces the amount of wind erosion through indirect action.Therefore,the harm of wind erosion can be reduced by appropriately increasing planting density,increasing roughness and crop coverage.