Effects Of Sugarcane Leaves Amendments To Different Soil Depth And Biosurfactant On Soil Nutrition And Microbial Community

Crop straw is the world's most abundant and renewable biomass resource.The use of straw as an organic fertilizer effectively maintains and enhances soil fertility and helps increase soil microbial diversity and activity.Chemicals,such as biosurfactants,have been widely valued as emerging method in terms of improving straw efficiency in the field.Soil acidification and degradation are major obstacles of sugarcane in China,and the use of sugarcane leaves amendments as organic fertilizers have been recognized as an effective way to improve the soil fertility.However,studies on the effects of sugarcane leaves amendments at different soil depth and biosurfactant application influence soil nutrient and microbial community have been rarely reported.Thus,this study was conducted to determine the impact of sugarcane leaves amendments on microbial community structure,and activities at different soil depths(0,10,20,30cm)and the effect of biosurfactants(soybean phospholipid)applied using10,20,40 mg/kg,on soil nutrients was also observed.The study found that,as the soil depth increased,the decrease in soil available nutrient was also observed between the range of 0-20 cm.1)At the soil depth of 0-10 cm of soil layer sugarcane leaves amendments significantly increased available potassium(AK),pH,soluble carbon(DOC),and soluble nitrogen(DON)(p<0.05).At thedepth of 10 cm the total carbon(TC),total nitrogen(TN),soluble carbon(DOC)and soluble nitrogen(DON)content at 10-20 cm of soil layer significantly increased(p<0.05).Sugarcane leaves amendments significantly increased urease activity at the between the depth of 0-20 cm(p<0.05),and microbial diversity and community's composition.2)This study shows that soil pH,DOC,TC and TN have significant responses to sugarcane leaves amendments.In addition,a significant effect was observed in soil microbial communities in terms of structural characteristics during sugarcane growth.The above soil quality indicators were chosen to assess the effects of sugarcane leaves amendments on soil nutrient status,which may also contribute to future research.3)The results of this study also suggested that sugarcane leaves amendments can influence specific soil microbial populations.During the study,proteobacteria was found to be highly abundant in the entire soil profile.The relative abundance of Alphaproteobacteria,Enterobacteriales,and Sphingomonadales also increased which are involved in organic matter metabolism.The relative abundance of ?-proteobacteria in vertical soil profiles(10-40 cm)was significantly higher than in other crops,and this unique result should be considered for further research and discussion.4)This study demonstrated that at different sugarcane growth stages,adding different concentrations of biosurfactant with sugarcane leavesamendments to the field enhanced soil nutrient and enzymatic activities,such as AP,AK,pH,DOC.The treatment with a lower concentration of biosurfactant(PLS1)significantly increased AK,DOC,pH(p<0.05).The regimes with a medium concentration of biosurfactant(PLS2)significantly enhanced the soil AP,AK,DON,pH(p<0.05).Low and medium concentration biosurfactants(PLS1 and PLS2)have better improvement effects than high concentration treatments(PLS3).5)In addition,the study found that the addition of biosurfactants with sugarcane leaves amendments significantly affect the abundance of disease resistance genus,such as Talaromyces of the family Trichocomaceae.Medium-concentration biosurfactants containing leaves significantly increased Gammaproteobacteria and Enterobacteriales,which are involved in the degradation of organic matter,and increased Pseudomonas abundance that inhibits plant diseases.