Effect of calco-magnesian amendment on the mineral weathering abilities of bacterial communities in acidic and silicate-rich soils

► We studied effect of Ca-Mg amendment on mineral weathering processes by bacteria. ► Total bacterial biomass was unaffected, but cultivable bacterial biomass increased. ► The use of carbon substrates increased in relation to season change and amendment. ► A more effective weathering was observed with bacteria extracted from amended soils. ► It was related to greater release of more or less chelating organic acids.