Study On Growth Of Ryegrass In Artificial Soil Based On Solid Waste

With the continuous advancement of urbanization and rapid development of industrialization,people’s quality of life and economic strength have been improved,but also brought a lot of environmental problems,especially the environmental pollution caused by solid waste can not be effectively recycled.Some solid wastes contain nutrients and structures similar to natural soils,which provides the conditions for the preparation of artificial soils from solid wastes.In recent years,some countries began to use artificial soil to improve degraded soil,and the research results also proved that artificial soil can improve soil pollution.In this study,low-cost and common solid wastes(domestic sludge,fly ash,earthworm manure,chicken manure)were selected as raw materials and mixed and cultured in different proportions to produce artificial soil.The study started from three aspects:First,the above four raw materials were mixed in different proportions for short-term culture,and the combination of soil close to neutral was selected according to the changes of pH and EC values for the next experiment;Secondly,the selected combinations were cultured for a long time,after which the basic physical and chemical properties,nutrient content,available heavy metal content and aggregate composition were measured to evaluate the properties of artificial soil.Finally,a pot experiment of ryegrass was carried out to explore the main factors affecting plant growth in artificial soil by measuring its biomass,nutrient content and trace element content,and to explore the application effect of artificial soil.The main results of this study are as follows:(1)Domestic sludge,fly ash,earthworm manure and chicken manure were selected as raw materials,and mixed culture was conducted in different proportions for one month.The results showed that the lowest pH value was 7.35 when earthworm manure was added on the basis of domestic sludge and fly ash 3:1.The pH and EC values of the chicken manure treatment group were higher than those of the earthworm manure treatment group.Therefore,the combination with the ratio of domestic sludge to fly ash of 3:1,3:2 and 4:1 and the combination with earthworm manure added on this basis were selected as the treatment for subsequent experiments.(2)The selected 6 combinations were cultured for a long time to explore whether the addition of vermicompost had an effect on the physical and chemical properties,nutrient content,available heavy metals and aggregate distribution of artificial soil.The results showed that the pH values of the six artificial soils were neutral,ranging from 6.93 to 7.49.The contents of available nutrients n,P and K increased with the increase of sludge and vermicompost.Application of vermicompost increased>The maximum number of 0.25mm aggregate was 81.94%of the sixth treatment.The content of available heavy metals decreased with the increase of earthworm manure usage.The content of macroaggregates is highly positively correlated with organic matter,and the cementation of organic matter increases the stability of macroaggregates.(3)The ryegrass pot experiment was carried out on the six combinations of artificial soil.The results showed that the number of the plant,plant height,leaf biomass,root biomass,N,P,K and trace elements Mn,Cu and Zn in treatments 4,5 and 6 were all lower than those in treatments 1,2 and 3,which might be due to the high salt content of vermicompost,which affected the normal growth of plants.