Effect Of Biogas Slurry Applying On Soil Quality In Vineyard And Grape Yield And Quality

Biogas slurry has been widely used in agricultural production due to its comprehensive nutrients,easy decomposition and lasting effects.Returning biogas slurry to farmland as liquid fertilizer can reduce the amount of chemical fertilizer and improve soil quality,which is conducive to the sustainable development of agriculture.In order to find out the effects of biogas slurry dosage and application years on soil quality and determine the application effects in Qilian grape sightseeing garden,field experiments were carried out for 2 years with fresh Balado Red grape as the material.The raw biogas slurry produced by normal anaerobic fermentation was used as irrigation fertilizer,the conventional chemical fertilizer was used as control and different proportions of biogas slurry for substitution and increase treatments were set.The effects of biogas slurry application on soil quality and grape production were studied by measuring the basic physical and chemical properties of soil,microbial function of soil and grape yield and quality,which were helpful to establish a reasonable fertilization system for grape cultivation in this area.The main results were as follows:1.Biogas slurry could effectively improve the soil physical properties,regulate the surface soil temperature and slow down the decline of soil moisture content in the grape growth period,but the improvement effects on surface soil bulk density,porosity and field moisture capacity were not significant.2.Biogas slurry could effectively improve soil fertility level and significantly increase the contents of soil organic matter and available nutrients.Compared with the application of chemical fertilizer,the contents of soil organic matter,available N,available P and available K were significantly increased by 43.8%~83.1%,12.5%~143.3%,34.7%~89.0% and 27.0%~110.7%,respectively.With the increase of application years,the contents of soil organic matter and available nutrients increased to a greater extent,among which 167% nitrogen treatment had a better application effect.3.Biogas slurry could significantly improve soil enzyme activitivies and soil microbial biomass carbon and nitrogen contents.As the application period increased,the activities of sucrase,urease and alkaline phosphatase in soil increased further and the activities of catalase in soil decreased.After biogas slurry application,soil microbial biomass carbon content significantly increased by 45.1%~186.2% and soil microbial biomass nitrogen content significantly increased by 14.0%~95.3%,with the increase in biogas slurry application years.In general,the effects of replacing 33% nitrogen and increasing 133% and 167% nitrogen treatments were better.4.Biogas slurry could effectively improve the metabolic activity of soil microbial community,among which the best effect was achieved by replacing 33% nitrogen treatment.Under this treatment,soil microbial carbon source utilization ability was stronger and overall metabolic activity was higher,which was 1.03%~5.80% higher than that of chemical fertilizer application.With the increase of application years,the differences between the treatments increased.At the same time,increasing nitrogen treatments(especially 133% and 167%)had more advantages than substitute nitrogen treatments in improving the ability of soil microbial carbon source utilization.The utilization rate of amino acid,carboxylic acid and polymer carbon source increased 2.3%~33.2%,15.5%~35.8% and 5.1%~10.3%,respectively.The utilization rate of phenolic acid and amine carbon source increased 7.7%~103.4% and 11.0%~56.1%,respectively.5.Biogas slurry could significantly improve grape yield components and increase grape yield,but grape quality decreased.After biogas slurry application,the specific leaf weight,chlorophyll content,single grain weight,grain number,ear number and plant yield were significantly increased.The effect of biogas slurry treatments on soluble solid content was not significant while the content of organic acid was significantly increased.With the increase of application years,the number of grains per ear and the weight of fruit ear increased further,the increase of plant yield increased,and the difference of soluble solid and organic acid contents in fruits between different treatments decreased.In terms of the yield and quality of grape fruits,the application of nitrogen replacement with 33% and 67% were more effective.Taking the effects on soil physical and chemical properties,soil microbial function and grape production into consideration,we concluded that the application effects of replacing 33% nitrogen and increasing 167% nitrogen treatments were better.