Study On Soil Erosion Control Measures And Effects Of Chestnut Forest In Miyun

Chestnut is a traditional tree species in China which has a history of hundreds of years.The chestnut forest in Miyun,Beijing,due to the loose soil under the forest,the exposed surface,and the lack of scientific management,the soil erosion of which is serious,and the current attention to it is not enough.In this article,the slope-lined chestnut forest in Miyun District is taken as the research object.During the period from April to November 2018,a combination of field simple runoff plots and brazing plots and indoor analysis and determination is used to lay out Simple runoff plots with natural recovery,planting of cypress,laying of coconut silk rug,straw curtains,artificial weeding,planting rehmannia,planting alfalfa,planting purslane and laying pebbles,to explore the characteristics of these measures to produce and produce sand under natural rainfall conditions.Through field investigation,the soil and water conservation benefits of different treatment measures are analyzed and summarized,in order to provide technical support for the effective prevention and control of soil erosion in chestnut forest land in this area.The following is conclusion:(1)The surface soil water content of different treatment measures is consumed in large quantities due to the rapid growth of plants from mid-June to early July,the soil surface water content shows a gradual decrease trend,After the arrival of the July-September flood season,the surface soil water content showed a significant increase trend,Soil surface water content increases with increasing rainfall.For different soil and water conservation measures,the surface water content of the soil is the highest in the purslane plot,followed by the alfalfa and the rehmannia,the cypress plot is the lowest,and the artificial weeding plot is higher than that of the cypress plot.(2)There are differences in soil physical properties between 0-50cm layers in different treatment measures.The total porosity and capillary porosity of 0-20cm layer in the alfalfa and the purslane plot are higher than other plot,and the unit weight is lower than other plot,and the total number of artificial weeding plot porosity and capillary porosity are lower than other plot,unit weight is higher than other plot,and the difference of pores in 30-50cm soil layer under different treatment measures is not significant.(3)The unit weight of the field of growing vegetation and the artificial weeding plot were 1.72 g/cm3 and 1.87 g/cm3,respectively;The total porosity is 38.07%and 28.45%,respectively;The capillary porosity is 35.82%and 26.13%,respectively;The available potassium content was 75.4mg/kg and 46.94mg/kg,respectively;The organic matter content is 7.05 g/kg and 4.52 g/kg,respectively;The ammonium nitrogen was 3.41 mg/kg and 3.91 mg/kg,respectively;the nitrate nitrogen was 12.04 mg/kg and 14.57 mg/kg,respectively;The available phosphorus is 5.21 mg/kg and 4.87 mg/kg,respectively.Vegetation coverage under the chestnut forest can significantly improve the physical and chemical properties of the soil.(4)During the period of from May to October 2018,there are 13 rainfall which have runoff,the flow rates of different treatment measures were natural recovery of 2.92 mm,planting of cypress 4.20 mm,laying of coconut silk rug 5.05 mm,laying of straw curtains of 3.83 mm,artificial weeding 5.42mm,planting rehmannia 3.68mm,planting alfalfa 2.39mm,planting purslane 3.24mm,laying pebbles 1.39mm,The runoff coefficients were 8.15%for natural recovery,11.72%for planting cypress,14.10%for laying coconut silk blankets,10.69%for laying straw curtains,15.13%for artificial weeding,10.26%for planting rehmannia,6.68%for planting alfalfa,and 9.04%for planting purslane.Laying pebbles 3.88%.The effect of laying pebbles is best,and artificial weeding is the worst.All kinds of measures can effectively reduce soil erosion under class forest.(5)During the period of from May to October 2018,there are 13 rainfall which have sediment production,the flow rates of different treatment measures were natural recovery of 1.72 kg,planting of cypress 1.810 kg,laying of coconut silk rug 2.0 kg,laying of straw curtains of 1.82 kg,artificial weeding 2.24 kg,planting rehmannia 1.75 kg,planting alfalfa 1.72 kg,planting purslane 1.83 kg,laying pebbles 1.50 kg,The effect of laying pebbles is best,and artificial weeding is the worst.All kinds of measures can effectively reduce soil erosion under class forest.(6)The soil loss under the chestnut forest decreased with the increase of forest vegetation coverage,the soil loss rate slows down;When the vegetation reached 80%,the soil loss was reduced by 41.31kg/m2 compared with bare land.It shows that vegetation cover can effectively reduce soil loss under chestnut forest.(7)The management of soil erosion under chestnut forest should be combined with the actual situation in the local area,while constructing the tree shroud to protect the slope,plant low-land alfalfa,purslane,and cypress to improve the coverage of chestnut forest land,at the same time does not affect farmers harvesting chestnuts.