Effects Of The Sweet Potato Stalks And Their Biochar To Field On Soil Physicochemical Properties And Microbial Community In Upland Red Soil

In view of the poor quality of red soil in dryland,low productivity,poor fertilizer retention,lack of nutrients,and most of the problems of stickiness,weight,plate and knot,this study is based on the field test of red soil in the dryland,and the experiment is to set up sweet potato stalks and its biochar There are 5 treatments in the field:conventional management(CK),3000 kg/ha sweet potato stalks returning field(S1),6000 kg/ha sweet potato stalks returning field(S2),1050 kg/ha sweet potato stalks biochar returning field(BC1)And 2100 kg/ha sweet potato stalks biochar charcoal(BC2).The effects of sweet potato stalks and its biochar returning on the physicochemical properties,soil enzyme activities,microbial community structure and crop yield of red soil in dryland were studied in order to provide theoretical basis and practical guidance for improving red soil in dryland,improving fertility of red soil in dryland and increasing crop yield.The main findings are as follows:(1)Sweet potato stalks and its biochar returning to the soil reduced the soil bulk density and increased the soil Eh.The weight loss of the soil was up to 0-10cm,the soil layer BC2 treatment was 4.26%,and the soil Eh increased by 0-10cm soil layer BC2.The treatment reached 7.09%;the sweet potato stalks returned to the field increased the soil dissolved organic carbon,and the sweet potato stalks biomass returned to the field reduced the soil dissolved organic carbon,the highest increase of 0-10cm soil layer S2 treatment reached 16.80%,the maximum reduction was 20 The BC2 treatment of-30cm soil layer reached 29.14%;the sweet potato stalks and its biomass carbon returning increased the soil hydrolyzed nitrogen and available phosphorus content,and the highest increase of hydrolyzed nitrogen and available phosphorus content was 0-10cm soil layer BC2 treatment reached 23.59%and 25.63%.(2)The sweet potato stalks returning field promoted the soil FDA hydrolase and urease activity,and had no obvious effect on the sucrase activity.The FDA hydrolase activity increased by 20-30cm,the S2 treatment reached 29.99%,and the urease activity increased the most.The S2 treatment of 10-20cm soil layer reached 25.59%;the biochar returning field showed the inhibitory effect on the FDA hydrolase and urease activities as a whole,and the BC2 treatment with the highest reduction of 0-10cm soil layer and 20-30cm soil layer respectively Up to 34.84%and 11.72%,the biochar returning to the field showed a promoting effect on the sucrase activity as a whole,and the increase was up to 27.35%in the 20-30 cm soil layer BC2 treatment.(3)Both sweet potato stalks and low-dose biochar returning treatment(BC1)can increase the total amount of soil microbial PLFAs,the highest increase is 20-30cm soil layer S1 treatment up to 18.34%,high-dose biochar returning field treatment(BC2)is reduced The total amount of soil microbial PLFAs was up to 23.16%,which changed the microbial community structure.The relative abundance of soil bacteria(gram-positive and Gram-negative bacteria)in the 0-10 cm,10-20 cm and 20-30 cm soil layers is 64.8%-69.66%,which is the dominant flora,followed by Actinomycetes were 18.92%-25.41%.(4)Sweet potato stalks and its biochar returning to the field have different effects on increasing sweet potato yield and economic benefits in red soil in the dry land.The sweet potato stalks half-returning field(SI)can significantly increase sweet potato yield,total biomass and economic benefits,and the sweet potato stalks is returned to the field(S2)reduced sweet potato yield,total biomass and economic benefits;sweet potato stalks biochar returning to the field is conducive to increasing sweet potato yield,but in terms of economic benefits,low-dose sweet potato stalks biochar returning to field(BC1)is positive economic benefit,high The dose of sweet potato stalks biochar returning field(BC2)is a negative economic benefit.In summary,sweet potato stalkss returning to the soil to some extent improved soil physical and chemical properties,soil enzyme activities,microbial community structure,sweet potato stalks biomass carbon returning to a certain extent has little effect on soil physical and chemical properties,soil enzyme activities,microbial community structure There is even a negative effect.Considering the overall economic benefits and new economic benefits,the one-year Daejeon positioning test data shows that the effect of half a sweet potato stalks returning field(S1)is optimal.