Salt stress impedes normal development, compromises plant quality, and reduces crop yield. The germination phase in soybean marks the initial stage of its growth cycle. Characterizing salt tolerance during this period can help stimulate soybean growth in natural environments and aid the rapid screening of salt-tolerant soybean varieties. Our study characterized the salt tolerance of 36 soybean germplasms in culture dishes during the germination period. Soybeans were subjected to varying concentrations (0, 60, 120, and 180 mmol/L) of NaCl solution to simulate diverse levels of salt stress, and parameters such as germination energy, germination rate, and root length were measured. Statistical techniques such as analysis of variance, membership function, cluster analysis, and quadratic regression equations were used, and the salt tolerance of these 36 soybean germplasms was determined. The critical indicators and the most effective screening concentration for assessing the germination salt tolerance of soybean were identified. Soybeans tolerated low salt concentrations; however, salt concentrations greater than 120 mmol/L significantly inhibited germination indicators. The germination rate, germination vigor, vitality index, seed germination index, total fresh weight, and total dry weight could be used to identify salt tolerance. The semi-lethal concentration of soybean was 155.4 mmol/L, and the coefficient of variation was 20.00%, indicating that it could be used as a screening concentration for evaluating salt tolerance during soybean germination. A total of 36 soybean varieties were classified into four salt tolerance levels through cluster analysis. QN-27, QN-35, and QN-36 were highly salt-resistant materials, and QN-2, QN-17, and QN-19 were salt-sensitive materials. Characterizing salt tolerance during soybean germination can facilitate the selection and breeding of salt-tolerant soybean varieties. Future research utilizing this approach can aid in the selection of soybean varieties with salinity tolerance.

Growth stage alters substrate availability and moisture in oats, potentially driving microbial succession and metabolite formation during ensiling. Oats were harvested at flowering (FS), milk ripening (MS) and wax ripening (DS) stages and vacuum-bag ensiled for 120 d (n = 4 per stage). We measured chemical composition and fermentation products, enumerated key microbes, profiled bacterial communities by 16S rRNA gene amplicon sequencing, and characterised metabolites by untargeted LC–MS. With advancing growth stage, dry matter (DM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) increased, whereas crude protein (CP) decreased. MS silage had the lowest pH (4.63) and the highest CP, whereas FS showed higher lactic acid, but the butyric acid (BA) and NH₃-N/TN were also significantly higher than those at MS and DS (p < 0.001). Community composition shifted from Enterobacter (FS) toward Lactobacillus enrichment (DS), accompanied by stage-specific metabolite signatures (biogenic amines and indoleacetic acid at FS; betaine and purine metabolites at MS; reduced amines and more amino-acid derivatives at DS). Overall, under the conditions of this study, considering fermentation stability, nutrient preservation, microbial diversity, and metabolic pathways, the best balance was achieved during MS.