Preliminary Study On The Effect Of Anaerobic Digestate On Plant Growth And Soil Properties

In recent years,anaerobic digestion has become an important technology in the emerging green energy technology,mainly consisting of two products: digestate and biogas.Anaerobic digestate is the residue of biodegradable raw materials after anaerobic digestion.It is a special nutrition that can be used as fertilizer and feed additive.Anaerobic digestate is considered as a potential biofertilizer because it is a source of recoverable trace elements and micronutrients for plant growth.Based on an understanding of the current state of integrated use of anaerobic digestate,this article applies anaerobic digestate to irrigate and grow ryegrass,tomato,cabbage,radish and white mustard seeds to investigate the effects of anaerobic digestate irrigation on seed growth,thus exploring its role in promoting plant germination and growth,and to assess the potential risk of soil damage and contamination.The results of the study show:(1)When the original digestate is applied,the germination potential of cabbage and radish increases by 24.94% and 23.78% respectively compared to tomato,indicating that cabbage and radish seeds are more vigorous and emerge flush and strong;the germination rate of cabbage and radish increases by 16.62% and 14.26% respectively compared to tomato,indicating that among the five different seed types,tomato is less tolerant to toxicity,while cabbage and radish are more tolerant.(2)Seed growth is associated with the use of anaerobic digesting solution.Diluted anaerobic digest contains low concentrations of ammonia nitrogen,which will reduce the toxic effects and improve root development,so seeds to which diluted digestate has been applied can germinate and grow normally.(3)The organic acids and nutrients in the anaerobic digestate are able to enhance the heavy metal content of the soil,and there is a tendency for heavy metals to accumulate in soil that has been watered with anaerobic digestate over time.The heavy metal content of the soil is related to the concentration of the anaerobic digestate and soil watered with dilute digestate is more likely to absorb metals.(4)Diluted digestate becomes more clarified,less odorous and of a more consistent quality than the original digestate,and when mixed with the soil,the heavy metal levels of the soil are all within the limit and does not cause excessive soil contamination,making it more environmentally friendly.Research has shown that combining the treatment and utilization of anaerobic digestate can provide a method for both the treatment of anaerobic digestate and the utilization of the nutrients in the digestate.