The long-term applications of different fertilizers (chicken manure, swine manure, and organic fertilizer) on the microorganisms of a corn field were investigated. The microbial communities during four periods (seedling, three-leaf, filling and mature periods) were comprehensively studied with molecular biology technology. Results showed that most nutrient contents (organic matter, nitrogen, phosphorus, and potassium) and levels of several heavy metals (As, Pb, and Cr) in the chicken and swine manures were higher than those in the organic fertilizer. The alpha diversity varied during the long-term fertilization, and the chicken manure was the best fertilizer to maintain the abundance of microorganisms. The microbial community of soil changes over time, regardless of the addition of different fertilizers. The correlations between environmental factors and microbial communities revealed that nutrient substances (available nitrogen, available potassium, and NO₃-N) were the most significant characteristics with the chicken and swine manures, while organic matter and nitrogen exhibited similar effects on the microbial structure with the organic fertilizer. The Pearson correlations of environmental factors on genus were significantly different in the organic fertilizer tests compared with the others, and Pseudomonas, Methyloligellaceae, Flavobacterium, and Bacillus showed significant correlations with the organic matter. This study will provide a theoretical basis for improving land productivity and sustainable development in corn fields.

Spartina alterniflora is recognized as one of the most detrimental invasive species along China’s coastlines, highlighting the need for effective and environmentally safe management strategies to preserve intertidal zones. This study assessed the effectiveness of combining plant growth regulators (PRGs) with physical cutting to manage S. alterniflora, using 16S rRNA and 18S rRNA gene sequencing to evaluate the impacts on the plant and associated soil micro-organisms. The results showed that compared to the control (CK), the regeneration numbers for treatments with abscisic acid (ABA), gibberellin (GA), paclobutrazol (PP₃₃₃), garcinol (GC), and glyphosate (GP) decreased by 29.75%, 23.25%, 15.75%, 94.50%, and 40.50%, respectively. Comparative analysis revealed no statistically significant variation in the inhibitory effects of ABA and GP on the germination of S. alterniflora (p > 0.05). Additionally, applying PRGs and herbicides increased the diversity indices of soil bacteria and fungi. Principal Coordinates Analysis (PCoA) showed that the impact of PRGs on the fungal community was less pronounced than that of herbicides. Significant differences were also noted in the abundance of microbial functional genes related to methanotrophy, hydrocarbon degradation, and denitrification compared to the control (p < 0.05). This study aimed to assess the potential of PRGs in controlling the invasion of S. alterniflora and to elucidate their impacts on soil microbial communities and functional gene expression.