Effects Of Lonicera Japonica On Soil Erosion And Phosphorus Loss In Gneiss Sloping Fields Under Simulated Rainfall

Mountain Area in Hebei province is an essential part of the northern earth-stone mountain area,and it is also a concentrated distribution area of gneiss.Meanwhile,it is the ecological barrier and resource supply area of the North China Plain.However,the gneiss soil layer has some special characters,for instance,solum is a little more thin,and its aggregate structure is not well.So water and soil loss is easy to occur in the area,and soil is washed by rainwater.The purpose of this dissertation is to explore the role of Lonicera japonica with different tree-ages（one,three and six years）in the process of controlling soil erosion and phosphorus loss in Taihang Mountain gneiss area.In order to provide basic scientific support in controlling soil erosion and protecting ecological environment,adopting design technique of randomized block of multifactor,we studied the law of runoff and sediment and the loss of phosphorus in gneiss soil,and also explained soil erosion resistance both in soil aggregate and root biomass by using artificial simulated rainfall equipment.The main conclusions are as follows:（1）Honeysuckle can obviously delay the initial runoff production time under different slopes.Compared to the bare land,the one,three and six years old Lonicera japonica were delayed by 10.71%,23.33%and 39.20%respectively on the slope of 20°.The increase of slope can lead to the initial time of runoff production occurred quickly,and the maximum amplitude is 20.69%under the slope of 26°.The standardized fitting equation between the initial runoff time T,the age of the honeysuckle A and the slope B is is T=0.833A-0.538B,R²=0.980.（2）Honeysuckle can reduce runoff and sediment contents,reduce runoff modulus,runoff depth and sediment modulus.It has the effect of reducing runoff and sediment,controlling soil erosion.On the slope of 20 degree,compared to bare land,one,three and six years old Lonicera japonica reduced runoff modulus with 20%,50%and 75%respectively,runoff depth with 20%,37%and 51%respectively and sediment modulus with 23.42%,57.60%and 68.46%respectively.The soil erosion in different slopes go from head erosion on 26 degrees bare land to one year’s Honeysuckle land of 26 degrees slope and 23 degrees bare land and then down to 20 degrees bare land and then down to one year’s Honeysuckle land of 23 degrees slope then down to one year’s Honeysuckle land of20 degrees slope and then down to three years of Honeysuckle land of 26 degrees slope and then down to three years of honeysuckle slope of 23 degrees and then down to six years of Honeysuckle land of 26 degrees slope and then down to six years of honeysuckle slope of 23 degrees and then down to three years of honeysuckle slope of 20 degrees and finally to six years of honeysuckle slope of 20 degrees.On steep slopes,one-year-old honeysuckle has no significant effect on sand reduction.（3）Honeysuckle can reduce the loss of AP and control soil phosphorus loss.On the slope of 20 degree,compared with bare land,the one,three and six years old Lonicera japonica decreased the effective phosphorus loss by 34.59%,72.34%and 82.12%and the total phosphorus loss rate by 20.67%,29.20%and 38.55%respectively.The order from large to small about AP nutrient loss in different slopes is 26 degrees bare land,23 degrees bare land and one year’s Honeysuckle land of 26 degrees slope,20 degrees bare land,one year’s Honeysuckle land of 23 degrees slope,one year’s Honeysuckle land of 20 degrees slope,three years of Honeysuckle land of 26 degrees slope,three years of honeysuckle slope of 23 degrees,six years of Honeysuckle land of 26 degrees slope,three years of honeysuckle slope of 20 degrees and six years of honeysuckle slope of 23 degrees and six years of honeysuckle slope of 20 degrees last.On steep slopes,it is suggested that more than three years old honeysuckle should be planted to control the loss of total phosphorus.（4）Gneiss soil aggregate resistance to erosion is weak,and particle size 0.5⁵ mm of soil aggregates are easy to disperse and crush.80 mm/h rainfall has a destructive effect on soil aggregates,but honeysuckle coverage can reduce the destructive effect of 80 mm/h rainfall.On the slope of 26 degree,compared to the bare land,the WAS_0.25 of the one,three and six year old honeysuckle slopes increased by 101.96%,184.97%and 118.30%respectively.The relationships were significant positive correlations between root biomass and total reduction rate of runoff and sediment,and correlation coefficient were 0.801and0.911.The relationships were significant negative correlations between root biomass and the content of phosphorus loss,and correlation coefficient was 0.743.To sum up,Honeysuckle can control soil erosion and phosphorus loss on the slope of gneiss and improve soil erosion resistance to some extent.