Trichoderma asperellum improves soil microenvironment in different growth stages and yield of maize in saline-alkaline soil of the Songnen Plain

The Songnen Plain is an important agricultural base in China and one of the important areas of distribution of saline-alkaline soils in the cold region. Saline-alkaline soils severely restrict maize growth. This study was to potentially promote the soil nutrient in the maize rhizosphere, microbes diversity, and maize yield by Trichoderma asperellum in saline-alkaline soil of the cold region. In the present study, we applied different amounts of T. asperellum in field experiments for three consecutive years. High-throughput sequencing was used to analyse the impact of Trichoderma on microbes diversity in maize rhizosphere soils. Changes in crop yield and soil nutrients were also monitored. T. asperellum treatment significantly increased the relative abundance of beneficial microbes genera. In the control treatment, the pathogenic microbes were the dominant genera. Pearson's correlation analysis revealed that changes in the soil microbial community composition were closely related to soil nutrients and were highly correlated with T. asperellum treatment concentration. Further, T. asperellum treatment increased crop yield by 4.87-20.26%. These findings suggest that T. asperellum treatment optimised the microenvironment of the maize rhizosphere soil, alleviated microbial community degeneration in cold region saline-alkaline soil, and promoted maize growth.