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Medicago ruthenica is a forage legume crop that is widely used as fodder and for ecological restoration in arid and semi-arid areas in Northcentral Asia. During the seedling stage, weeds challenge the growth and development of M. ruthenica, especially in fields sown for seed production. However, strategies to effectively control weeds in crops of M. ruthenica using herbicides have not been investigated. We evaluate the efficacy of different herbicides that control pre- and post-emergence of weeds in M. ruthenica. The results indicated that the most effective pre-emergence herbicides, imazethapyr (1530 mL ha⁻¹) and flumetsulam (120 mL ha⁻¹), resulted in crop safety and soil microbial community equivalent to a weed-free check. The most effective post-emergence herbicides are imazethapyr + haloxyfop-P (1800 + 600 mL ha⁻¹) and 2,4-DB + haloxyfop-P (2250 + 600 mL ha⁻¹). These herbicide treatments demonstrate effective control of most weeds (A. retroflexus, C. album, and grasses) while ensuring crop safety. Application of these herbicides to control weeds in M. ruthenica prior to or after their emergence represents a viable strategy for their control and also improve agricultural viability and crop yield and quality. Our research contributes to sustainable agriculture and ecological restoration in arid regions. Full article

As one of the environmental factors that seriously affect plant growth and crop production, drought requires an efficient but environmentally neutral approach to mitigate its harm to plants. Soil microbiomes can interact with plants and soil to improve the adverse effects of drought. Medicago ruthenica (L.) is an excellent legume forage with strong drought tolerance, but the key role of microbes in fighting drought stress remains unclear. What kind of flora plays a key role? Is the recruitment of such flora related to its genotype? Therefore, we selected three varieties of M. ruthenica (L.) for drought treatment, analyzed their growth and development as well as their physiological and biochemical characteristics, and performed 16S rRNA high-throughput sequencing analysis on their rhizosphere soils to clarify the variety-mediated response of rhizosphere bacteria to drought stress. It was found that among the three varieties of M. ruthenica (L.), Mengnong No.2, Mengnong No.1 and Zhilixing were subjected to drought stress and showed a reduction in plant height increment of 24.86%, 34.37%, and 31.97% and in fresh weight of 39.19%, 50.22%, and 41.12%, respectively, whereas dry weight was reduced by 23.26%, 26.10%, and 24.49%, respectively. At the same time, we found that the rhizosphere microbial community of Mengnong No. 2 was also less affected by drought, and it was able to maintain the diversity of rhizosphere soil microflora stable after drought stress, while Mennong No. 1 and Zhilixing were affected by drought stress, resulting in a decrease in rhizosphere soil bacterial community diversity indices to 92.92% and 82.27%, respectively. Moreover, the rhizosphere of Mengnon No. 2 was enriched with more nitrogen-fixing bacteria Rhizobium than the other two varieties of M. ruthenica (L.), which made it still have a good ability to accumulate aboveground biomass after drought stress. In conclusion, this study proves that the enrichment process of bacteria is closely related to plant genotype, and different varieties enrich different types of bacteria in the rhizosphere to help them adapt to drought stress, and the respective effects are quite different. Our results provide new evidence for the study of bacteria to improve the tolerance of plants to drought stress and lay a foundation for the screening and study mechanism of drought-tolerant bacteria in the future. Full article