Abstract: 【Objective】 To explore the salt-reducing effect of microbial fertilizer to different degrees of saline soil and the growth response of winter wheat. 【Methods】 Coastal saline soil was used to create mildly,moderately,and heavily salined soils.Yi'an improved soil remedial 2 bacteria agent was selected. Fertilization gradient of 750,1500 and 2250 kg/hm² were set to compared and analyze soil salt content,winter wheat plant height,SPAD value,fresh weight,root length. 【Results】 The application of microbial bacterial fertilizers to different degrees of saline soil had some salt-reducing effect,and the soil salt content decreased by 6.02%-36.27% compared with the control. The mildly salinization treatment with a microbial fertilizer application rate of 1500 kg/hm² had the most obvious salt reduction effect. Application of microbial fertilizer treatment compared with the control,the plant height of winter wheat increased by 18.01%-33.52%,SPAD value increased by 9.82%-24.30%,fresh weight increased by 10.53%-38.46%,and root length increased by 14.08%-32.19%. When the amount of microbial fertilizer was less than 1500 kg/hm²,the salt-reducing effect increased with the increase of the application amount,and the growth of winter wheat increased significantly. When the amount was more than 1500 kg/hm²,the salt-reducing effect increased slowly. 【Conclusion】 Application of microbial fertilizer in salinized soil of different degrees had obvious salt-reducing effect and significantly promoted the growth of winter wheat.

Key words: Microbial fertilizer, Soil salinity, Salt-reducing effect, Winter wheat, Growth index