Effects Of Different Mulching Measures On Physical And Chemical Properties Of Tree Pool Soil In Park Greenland

At present,There are large areas of bare tree pools,bare lawns,bare shrubs in China's urban greening,These bare areas will cause dust,reduce soil quality.and seriously affect the ecological beautification.At the same time,a large number of garden greening waste disposal pressure is also increasing every year,the current treatment methods are simple and few,which restrict the development and construction of ecological civilization.In this study,the control experiment and field experiment were designed to select the optimum mulching materials,thickness and methods,to improve the quality of urban greening and broaden the ways of gardening waste treatment.In the control experiment,three mulching materials(cobblestone,organic mulching pad and wood chips)and two mulching thicknesses(3cm and 6cm)were selected to explore the influence of different mulching naterials and thicknesses on the soil physical and chemical properties of 0-10cm,10-20cm and 20-40cm soil layers in the nursery.Selecting the better mulching thickness for field experiment.In the field experiment,five mulching material(wood chips,garden waste,pebbles,ceramsite,organic mulching pad)and two methods(single layer mulching,two layers mulching:mulching+garden waste composting),6cm mulching thickness(selected by control experiment)were designed to explore the effects of mulching for physical and chemical properties on 0-10cm,10-20cm and 20-40cm soil layer in the bare tree pool of the Old Summer Palace,Haidian District,Beijing,the results are as follows:(1)The results of the control experiment and the field experiment are roughly the same,but the mulching of the same material is more pronounced in the control experiment.The mulching treatments mainly affects the 0-10em and 10-20cm soil layers;With the increase of mulching time,the influence is greater;The thickness of mulching mainly affects the chemical properties of soil;the mulching with two layers has better effect on the physical and chemical properties of soil,and the validity is longer.(2)The mulching treatments can improve soil moisture content,and the effect is obvious in spring and autumn significantly.Pebbles and organic mulching pad have the better water retention and improvement effect.The influence of mulching treatments on soil temperature decreases with the deepening of soil depth.The organic mulching pad has the characteristics of "rising in winter and falling in summer",and pebbles will aggravate the change of soil temperature;All organic mulching materials can reduce soil bulk density and improve soil porosity and water holding capacity.The layering of garden waste is best to reduce soil bulk density and improve total soil porosity,capillary porosity.Pebbles can increase soil bulk density and reduce total soil porosity significantly.The layering of mulching to improve soil saturated moisture capacity,capillary moisture capacity,field moisture capacity are the best,and the effect is strengthened with the increase of mulching time.(3)The inorganic mulching materials have little influence on soil organic matter and available nutrients.All organic mulching materials can reduce soil pH value and improve soil organic matter content,available nutrients.Compared with the thickness of 3cm,the mulching thickness of 6cm increase more.Compared with single layer mulching,two layers mulching has more obvious improvement effect and stronger persistence.The durability of organic mulch mat layering is better than the garden waste layering.The effect of mulching treatments on soil pH are strengthened with the increase of mulching time(4)The layering of organic mulch mat,layering of garden waste,organic mulch mat and gardening waste can increase soil organic matter by 61.58%,54.26%,26.40%,14.52%;The contents of available P in soil were increased by 63.66%,54.35%,25.47%,11.26%;The content of soil alkali hydrolysable N matter were increased by 32.16%,30.73%,16.29%,5.59%;The contents of soil available K matter were increased by 19.36%,18.41%,8.48%,4.75%;The contents of soil total nitrogen were increased by 19.69%,14.96%,9.71%and 5.51%.The layering of organic mulch mat has the best comprehensive effect.