对北方寒地草场中栽培的苜蓿接种苜蓿根瘤菌,分别检测接种后不同生长阶段所结的根瘤数量和结瘤率,植株鲜重,产草量以及土壤肥力的变化.试验结果表明:接种根瘤菌明显提高结瘤率和结瘤量,增加植株鲜重,在改善牧草产量和品质的同时,增加了土壤中的有机质和速效氮含量,改善了土壤微生态环境.“,”The cultivated alfalfa in northern cold pastures was inoculated with Rhizobium meliloti, the nodulation volume and nodulation efficiency were detected after inoculation at different growth stages, plant fresh weight, grass yield and soil fertility changes.The results showed that:Rhizobium inoculation significantly increased the nodulation efficiency and nodulation volume,increased plant fresh weight,improved forage yield and quality, increased organic matter and available nitrogen in the soil and improved soil micro-ecological environment.