Effects of quicklime application on bacterial community structure and metabolic function in acidified tobacco-planting soil

Soil acidification is an important factor leading to the occurrence and spread of tobacco bacterial wilt. In this experiment, different amounts of quicklime were used to improve acidified tobacco-planting soil, and the effects of quicklime on structure and metabolic function of bacterial community in acidified soil and the relationships between soil bacterial community and environmental factors were analyzed.?The results showed that the appropriate amount of quicklime (1 200-1 500 kg/hm²) improved the Sobs, Shannon, Ace and Chao1 indexes of the bacterial community in acidified soil and the relative abundance of Actinobacteria, Chloroflexi and Myxococcota; increased the abundance of genes related to energy metabolism and the metabolism, translation, folding, sorting, and degradation of terpenoids and polyketides; while decreased the abundance of genes related to membrane transport. Therefore, an appropriate amount of quicklime (1 200-1 500 kg/hm²) could improve the structure and metabolic function of the bacterial community in acidified soil, and soil pH, exchangeable calcium, magnesium and aluminum contents were identified as important factors affecting soil bacterial community.