Abstract: This study investigated the relationship between silicon fertilizer and physiological indexes of alfalfa during overwintering and the influence of different winter irrigation treatments on the overwintering rate of alfalfa,and provided a new idea for ensuring the overwintering of alfalfa. The effects of winter irrigation and silicon fertilizer on cold resistance and overwintering rate of alfalfa were analyzed by comparing the differences of field soil temperature,soil volume water content and physiological indexes of cold resistance of plant root and neck during overwintering. The results showed that the overwintering rate was the highest under the treatment of maximum winter irrigation,and the soil temperature and volume water content were higher than other treatments during the overwintering. Silicon fertilizer increased the content of soluble sugar and free proline in the root and neck of alfalfa,reduce the content of malondialdehyde,and improved the cold resistance of alfalfa. The experimental results showed that winter irrigation can improve the overwintering rate of alfalfa.

Key words: Alfalfa, Winter Irrigation, Silicon fertilizer, Winter surviving rate

摘要： 本研究初步探讨了越冬期间硅肥与紫花苜蓿（Medicago sativa L.）越冬生理指标的关系以及不同冬灌处理对紫花苜蓿的越冬率的影响，为保障苜蓿越冬提供新的思路。本试验通过对比越冬期间田间土壤温度、土壤体积含水量及植株根颈部抗寒性生理指标的差异，分析了冬灌和硅肥对紫花苜蓿抗寒性、越冬率的影响。结果表明：越冬率最高的是最大冬灌水量处理的小区，且该处理越冬期间土壤温度和土壤体积含水量均高于其他处理，春季土壤解冻后深层土壤的含水量也高于其他处理；硅肥可提高紫花苜蓿根颈部可溶性糖、游离脯氨酸含量，并降低丙二醛含量，可提高紫花苜蓿的抗寒性。本试验结果初步证明冬灌可提高苜蓿越冬率。

关键词: 紫花苜蓿, 冬灌, 硅肥, 越冬率