Development Of High-efficiency Bioretention Filler With Wood Chip Biochar And Research Of Parameters Optimization

In order to increase the water and nitrogen utilization efficiency of deep p it infiltration irrigation under the condition of integrated water and fertilizer,thi s paper explores the infiltration capacity,humid front migration,wet body mois ture distribution of deep pit infiltration irrigation and soil in different influencin g factors through laboratory experiments Effects of ammonium nitrogen and nit rate nitrogen transport and transformation characteristics.The main research res ults are as follows:(1)Under deep pit infiltration irrigation and nitrogen fertilizer infiltration,the cumulative infiltration volume and infiltration time conform to the Kostiak ov power function infiltration model.Increasing the nitrogen fertilizer concentra tion and the opening rate of the irrigation device will lead to an increase in th e cumulative infiltration volume.On the other hand,reducing the initial water content and soil bulk density will also lead to an increase in the cumulative in filtration volume.(2)There is a certain power function correlation between the migration dis tance of each wet front and the infiltration time of the infiltration of nitrogen fertilizer in the deep pit infiltration irrigation.Under the premise of the same i nfiltration time,there is a significant negative correlation between the migration distance of the wet front in each direction and the bulk density of the soil,a nd there is a significant positive correlation between the initial moisture conten t of the soil and the porosity of the irrigation device..At the end of irrigatio the smaller the soil bulk density,the initial soil moisture content,the pore ope ning rate of the irrigation device,and the greater the nitrogen fertilizer concent ration,the greater the distance of the humid front migration.As the redistributi on progresses,the range of the wetted body becomes larger and the moisture distribution becomes more uniform.(3)The period of the end of irrigation and the redistribution of irrigation,the distribution of ammonium nitrogen should be concentrated near the water hole of the irrigation device,and the distribution characteristics of nitrate nitro gen and water have a certain similarity.After the irrigation is completed,the wet body is the same There is a significant negative correlation between the m ass fractions of ammonium nitrogen and nitrate nitrogen maintained by the nod e and the bulk density of the soil,and there is a significant positive correlatio n between the initial moisture content of the soil and the porosity of the irriga tion device.During the redistribution process,the nitrate nitrogen mass fraction in the moist body changed little during the first 3 days.From day 3 to day 10,the ammonium nitrogen mass fraction in the moist body decreased significa ntly;while the nitrate nitrogen mass fraction decreased from 3 days to 10 days gradually increased.(4)Hydrus-2D software can well simulate the soil water and nitrogen tran sport and transformation characteristics of deep pit infiltration irrigation.