| This research aimed the serious soil erosion in loess region of Shanxi province,which had low soil fertility and poor farming conditions.In order to solve this problem,the actual measures was to use complex or little effect.This study seek to use existing chemical material to set control measures to improve soil ecological environment.The research methods included:combination of macro and micro study,field experiment combining with laboratory experiments,short-term observation combining with long-term observation.Based on the principles of adjust measures to local conditions,this research firstly proposed the three-dimensional governance measures to control soil erosion and optimize soil ecological environment on 4 kinds land use types in loess area.Applying different material was aimed to find the most appropriate control measures for various land types,which could enhance the ability of soil resistance erosion,optimize soil mechanical composition,increase soil available water and improve soil fertility.This has been able to conserve soil and water and increase the utilizing efficiency of water and fertilizer,and it may ultimately come true the stability of loess soil environment and sustainable development.This study has put forward the effective method to optimization or reconstruction the soil ecological environment of the loess area,and it has provided a theoretical basis for soil ecological environment restoration and construction.The main results are as follows:(1)Studying the effect of different control measures on runoff and soil erosion in different rainfall intensity,the result showed a significant linear negative correlation between the initial flow time and rainfall intensity in all control measures,and a significant positive correlation between the runoff velocity and rainfall intensity,and between the surface runoff amount and rainfall intensity.The correlation of sediment concentration and rainfall intensity had a difference in treatments treatments:there was a significant linear positive correlation between sediment concentration and rainfall intensity in CK,an exponential correlative in C,S1C and S2C treatments,a quadratic function in S3C,S4C and S5C treatments.All the treatments could significantly reduce soil erosion and surface runoff amount,and when the rainfall intensity was less then 30mm/h,S5C was the best treatment with the highest sediment reduction benefit and flow reduction benefits.However,when the rainfall intensity was 40mm/h,S4C had the highest sediment reduction benefit and S5C had the highest flow reduction benefits.Beyond that,all treatments could significantly increase the soil infiltration rate and S5C had the highest soil infiltration rate in all rainfall intensity.Meanwhile,all treatments could significantly reduce the soil evaporation and S3C had the lowest soil evaporation,which might signify the ability to resist evaporation was not always positive correlation with super absorbent polymers(SAPs)content.In terraced fields SCF could increase sediment reduction effect by 34.81%,and 44.16%was in SCF in road slope,and the sediment reduction effect was increase by 21.02%,27.24%and 36.01%from 2014 to 2016,respectively.This showed control measures had remarkable effect on conserving soil in all land types and the effect is lasting a long time.(2)Studying the effect of different control measures on physical and chemical properties of soil,the result showed the soil soil bulk density and soil porosity in the treatments or next the treatments was changed by control measures in 4 land types.Meanwhile,the control measures could promote the development of soil aggregate and the large size soil aggregate was transforming from small particle diameter soil.In wasteland,S5C had the highest ability to increase large size aggregate content,and SCF had the highest ability in 0-10cm soil layer in terraced fields,but the highest content in 10-20cm.There was the larget big size aggregate content and the increasing rate of SCF in 0-10cm soil layer of road slope,and control measures could continue to increase significantly large size aggregate content from 2014 to 2016.When the air temperature was low,control measures could increase the soil temperature.Accordingly,it would reduce the soil temperature with a high soil temperature.In addition,the soil hydrothermal condition was influenced by treatments and soil available water was obviously increase in all land types.Soil organic content(SOC),total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),total potassium(TK)and available potassium(AK)were significant increased by control measures in the applying measures layer and next measures layer.(3)Studying the effect of different control measures on plant growth physiological indexes in 4 land types,the result showed vegetation coverage and plant richness was obvious increased by treatments in wasteland and road slope,which plant structure had been optimized.Control measures could increase maize seedling emergence rate and relatively advance maize growth process,whose water and fertilizer use efficiency and grain yield would improved remarkably.In the steep slope,control measures could promote root of Amorpha fruticosa development,and the element reserves in different organs were obvious increase.Then it might mean the control measures is effective in the 4 land types in the loess area,the experiment has practical significance and theoretical significance. |
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