生物炭对烤烟成熟期土壤养分及根际细菌群落结构的影响

Effects of biochar on soil nutrients and rhizosphere bacterial community structure of flue-cured tobacco at maturity stage

采用大田小区处理方式,分别设置常规施肥(CK)和750 kg/hm^(2)生物炭+常规施肥(T)2组试验,探究生物炭对植烟土壤微生物群落和土壤养分的变化规律及其对烟叶质量的影响。结果显示:生物炭可以显著提高土壤pH、速效磷、速效钾和有机碳含量,促进烟株生长发育;与CK相比,生物炭处理后绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteriota)和厚壁菌门(Firmicutes)丰度增加,分别提高了1.82%、12.36%和64.55%;放线菌门(Actinobacteriota)和变形菌门(Proteobacteria)丰度分别降低了2.02%和9.00%;聚类和主成分分析结果显示,烤烟根际土壤中优势细菌与土壤pH、速效钾、速效磷和有机碳均存在显著的相关关系,其中厚壁菌门(Firmicutes)、Myxococcota和Desulfobacterota与土壤pH、速效磷、速效钾和有机碳存在显著的正相关关系(P<0.05),Bacterdidota与Patescibacteria与土壤pH、速效钾、速效磷和有机碳存在显著负相关关系;生物炭施用通过改善根系周围矿质营养和微生物群落进而提高烟叶质量。生物炭有利于成熟期土壤养分固持及根际促生细菌群落增加。

Field plot treatment and two groups of experiments including CK(conventional fertilization)and T(750 kg/hm^(2)biochar+conventional fertilization)were used to study the effects of biochar on soil nutrients and rhizosphere bacterial community structure of flue-cured tobacco at maturity stage.The results showed that biochar significantly increased soil pH,the content of available phosphorus,available potassium and organic carbon,and promoted the growth and development of tobacco plants.Compared with CK,the abundance of Chloroflexi,Acidobacteria and Firmicutes increased by 1.82%,12.36%and 64.55%,respectively.The abundance of Actinobacteria and Proteobacteria decreased by 2.02%,and 9.00%,respectively.The results of cluster and principal component analyses showed that the dominant bacteria were significantly correlated with the soil pH,available potassium,available phosphorus and organic carbon.The Firmicutes,Myxococcota and Desulfobacterota were significantly positively correlated with soil pH,available phosphorus,available potassium and organic carbon(P<0.05).The Bacterdidota and Patescibacteria were negatively correlated with soil pH,available potassium,available phosphorus and organic carbon.Biochar application can improve the quality of tobacco leaves by improving the mineral nutrition and microbial community around the roots.Biochar is conducive to soil nutrient retention and growth-promoting bacterial communities in the rhizosphere during the maturity period of tobacco.It will provide a theoretical reference for regulating soil nutrition and microecological environment during tobacco maturity.