Climate variability and current farming practices have led to declining soil fertility and pH, with a heavy reliance on fertilizers and herbicides. The addition of forage and grain legumes to farming systems not only improves soil health but also increases farm profitability through nitrogen (N) fertilizer cost offsets. However, the formation of effective symbioses between legumes and rhizobia can be unreliable and is considered at risk when combined with dry sowing practices such as those that have been designed to obviate effects of climate change. This research was initiated to improve the robustness of the legume/rhizobia symbiosis in low pH, infertile and dry soils. Production from two cultivars of field pea (Pisum sativum) and two species of vetch (Vicia spp.), and symbiotic outcomes when inoculated with a range of experimental rhizobial strains (Rhizobium leguminosarum biovar viciae), was assessed in broad acre field trials which simulated farmer practice. New rhizobia strains increased nodulation, N fixation, produced more biomass and higher seed yield than comparator commercial strains. Strain WSM4643 also demonstrated superior survival when desiccated compared to current commercial strains in the laboratory and on seed when delivered as inoculant in peat carriers. WSM4643 is a suitable prospect for a commercial inoculant in Australia and other agricultural areas of the world where growing peas and vetch on soils generally considered problematic for this legume/rhizobia symbiosis. A particular advantage of WSM4643 may be that it potentiates sowing inoculated legumes into dry soil, which is a contemporary response by farmers to climate variation.

中文翻译：

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通过使用优良的豆科根瘤菌biovar viciae菌株，优化低pH土壤上的草料和谷物豆类的生长

气候变化和当前的耕作方式导致土壤肥力和pH值下降，严重依赖化肥和除草剂。在耕作系统中添加草料和谷物豆科植物不仅可以改善土壤健康状况，还可以通过抵消氮肥成本来提高农场的盈利能力。但是，豆科植物和根瘤菌之间形成有效的共生体可能是不可靠的，并且与诸如旨在消除气候变化影响的干法播种实践相结合时，被认为处于危险之中。这项研究的发起是为了提高低pH，不育和干燥土壤中豆类/根瘤菌共生的稳健性。两种豌豆（Pisum sativum）品种和两种etch子（Vicia）的产量。属物种），和共生结果当与一系列实验根瘤菌的（接种根瘤菌生物变种蚜），在模拟农民实践的大面积田间试验中进行了评估。与对照商业菌株相比，新的根瘤菌菌株增加了结瘤，固氮作用，产生了更多的生物量和更高的种子产量。与目前在实验室和种子中作为泥炭载体接种的种子相比，WSM4643菌株在干燥后的存活率也更高。WSM4643是在澳大利亚和世界其他农业地区用作商业接种剂的合适前景，在这些地区，通常认为这种豆类/根瘤菌共生存在问题的豌豆和野豌豆生长在土壤上。WSM4643的一个特殊优势可能是，它可以将接种的豆科植物播种到干燥的土壤中，这是农民对气候变化的当代反应。