Study On The Effects Of Reclaimed Materials To The Physical And Chemical Properties Of Garden Soil And Its Application

There is a huge output of construction waste in China every year,and its resource utilization has been paid much attention,especially its application in garden and horticulture has broad prospects.In this study,recycling granules of 0-2 mm,2-3 mm and 3-5 mm(FS1,FS2,FS3 for short)made from construction waste were mixed with garden soil according to the mixing amount of 10%,20%,30%,40%and 50%(A1,A2,A3,A4,A5 for short)of the mass ratio,and straw treatment was added as fertilizer to form planting substrate to plant a typical garden plant,platycodon grandiflorum.The effects of reclaimed materials on soil physical and chemical properties and plant growth were discussed.The main research results are as follows:(1)Reclaimed materials of construction waste contain a large amount of potassium,calcium,magnesium,iron,silicon and other elements needed by plants,which can be applied to garden soil for plant growth;The reclaimed construction waste material has a large surface area of 12.85 m~2/g,and its structure is conducive to the release of nutrients and the improvement of soil structure.(2)Reclaimed materials can reduce soil bulk density and increase soil porosity.The larger the particle size was,the more obvious the influence was on the soil bulk density and porosity.In the experiment,the minimum bulk density was reduced to1.20 g/cm~3,which met the requirements of planting soil for landscaping.The reclaimed materials can increase the soil capillary water capacity.(3)The reclaimed materials of construction waste can increase the content of available potassium,exchangeable potassium,exchangeable calcium,and reduce the content of exchangeable sodium and the degree of alkalization in soil,and the lowest alkalization is 9.69%in all treatments.(4)The variation trend of water-soluble cations in soil is similar to that of exchangeable ions.Reclaimed materials can increase the content of water-soluble potassium,calcium and magnesium in soil,and reduce the content of water-soluble sodium.The smaller the particle size of reclaimed materials,the more obvious the influence on water-soluble potassium and magnesium.The content of water-soluble cations in soil with straw was higher than that without straw.The reclaimed material increased the content of water-soluble sulfate in the soil,and the molar percentage of carbonate and bicarbonate decreased to 4.09%.When the reclaimed materials were used as much as 50%,the maximum soil EC value was 478.33μs/cm,which was in line with the requirement of planting soil index in garden soil.(5)The growth of platycodon grandiflorum was not significantly affected by the reclaimed materials of construction waste,while the addition of straw could significantly increase the plant height and biomass of platycodon grandiflorum.reclaimed materials and straw can improve platycodon grandiflorum growth.There was a high correlation between platycodon grandiflorum biomass and soil nutrients(P<0.05).The research results can provide reference and scientific basis for garden soil improvement and construction waste resource utilization.