LAUSR

Abstract Soil ameliorants can improve soil physico-chemical properties and activate microbial communities in saline-sodic soils. However, there has been less focus on how aggregate fractions affect soil microbial communities under different ameliorant applications. Here, we used the phospholipid fatty acid (PLFA) analysis to explore the effects of soil ameliorants on microbial communities within mega-aggregates (diameter of >2 mm, ME), macro-aggregates (diameter of 0.25–2 mm, MA), and micro-aggregates (diameter of  ME > MI. Meanwhile, the proportional abundance of arbuscular mycorrhizal fungi (AMF) varied between different aggregate fractions as follows: ME > MA > MI. Additionally, the DG treatment significantly enhanced the soil aggregate stability by increasing the AMF abundance, AMF/saprotrophic fungi ratio, and SOC content of the MI. Furthermore, soil microbial groups were highly correlated with soil SOC (P  0.25 mm diameter (P