Biofertilizer based on halotolerant microorganisms promotes the growth of rice plants and alleviates the effects of saline stress.

Abstract

Long-term soil salinization easily contributes to soil hardness, soil nutrient imbalance, and soil microbial diversity reduction, resulting in low rice yields in the salinized fields, and microbial remediation is one of the important measures to improve salinized soil. To verify the effect of biofertilizer based on halotolerant microorganisms on promoting rice growth and alleviating saline stress, this study discussed the effects of biofertilizer on soil microbial diversity and community structure and analyzed the correlation between the formation of microbial community structure and soil nutrient factors in the salinized field. The result, in comparison with applying inorganic fertilizer (referred to as CK), showed that notably increased soil available nitrogen, available phosphorus, available potassium, and rice paddy yield (p < 0.05) and significantly decreased soil electrical conductivity (p < 0.05) were achieved via biofertilizer (referred to as G2). Additionally, the application of biofertilizer contributes to the increase in soil microbial diversity and reorganization of microbial community structure, and through the analysis of linear discriminant analysis effect size, a notable difference in relative abundance was found in 13 genera, 6 families, and 3 orders between the control group and experimental groups (p < 0.05), and by linear discriminant analysis, Desulfomonas was further identified as the differentiated indicator. The redundancy analysis showed that available phosphorus and cation exchange capacity were the key environmental factors that affected microbial community structure and composition. Through bacterial functional prediction, increased rhizosphere soil bacterial metabolism, enzyme activity, membrane transport, and other potential functions were achieved by applying biofertilizer. Therefore, the application of biofertilizer could significantly alleviate rice growth stress and increase nutrient supply capacity in saline soil. These findings provide theoretical support for soil microbial improvement technology in the salinized field.