Abstract: In order to explore the effect of film mulching planting on the overwintering of Medicago in the alpine region of the Qinghai-Tibet Plateau, ‘Gannong No. 1’ Alfalfa Variety was used as the material, and alfalfa planting experiments with three mulching modes were carried out in Tianzhu Alpine Region of Wuwei City, Gansu Province. Taking ridge and furrow (RF) as a control group, and using film mulching on ridge and furrow (FMRF) and film mulching parallel to the ground (MPG) as the treatment group, the study analyzed the growth of alfalfa, soil water, temperature and nutrient. The results showed that the overwintering rate of alfalfa under FMRF and MPG increased by 25.76% and 23.79% respectively compared with RF, and the overwintering rate of alfalfa under film mulching was more than 88%. Film-mulching greatly increased the soil temperature and water content of the alfalfa field in the alpine region, MPG had the best temperature raising effect and increased the soil temperature by 2.3℃;FMRF increased soil moisture by 6.93% and had the best water preservation effect. As soil water content and temperature conditions improved, the nitrogen content of various forms and soil enzyme activities were also increased. Soil nitrogen and enzyme activities in the 0-30 cm soil layer were as follows:FMRF>MPG>RF. Soil urease activity was significantly positively correlated with ammonium nitrogen, nitrate nitrogen, total nitrogen, and alkali hydrolyzed nitrogen content (P<0.05). In Tianzhu alpine meadow and similar region, film-mulching can significantly increase soil temperature and water content (P<0.05), promote microbial activity, increase soil enzyme activity, and promote soil nitrogen cycle. Thus, it significantly increased the biomass and overwintering rate of alfalfa.

Key words: Alpine region, Film mulching, Soil water and temperature, Soil enzyme, Soil nitrogen

摘要： 为探究覆膜种植对青藏高原高寒区苜蓿（Medicago）越冬的影响，试验以‘甘农1号’杂花苜蓿为材料，在甘肃省武威市天祝高寒地区进行了3种覆盖模式的苜蓿种植试验，以垄沟（Ridge and furrow，RF）为对照，以垄沟覆膜（Film mulching on ridge and furrow，FMRF）和平作地膜（Film mulching parallel to the ground，MPG）为处理组，研究分析苜蓿生长当年的土壤水热及养分状况。结果表明：和RF相比，FMRF和MPG处理下苜蓿越冬率提高了25.76%和23.79%，覆膜下苜蓿越冬率达88%以上；覆膜可提高高寒区苜蓿地土壤温度和水分，和RF相比，MPG增温2.3℃，增温效果最佳，FMRF增加土壤水分6.93%，保墒效果最佳；土壤氮含量和土壤酶活性在土壤水热改善的基础上也得到增加，土壤氮含量和酶活性在0～30 cm各土层均表现为：FMRF>MPG>RF。在天祝高寒区及类似区域采用覆膜处理可以提升土壤温度和水分，促进微生物活动，使土壤酶活性增加，进而促进土壤氮素循环，使苜蓿种植当年的生物量和越冬率得到提高，且FMRF处理效果优于MPG。

关键词: 高寒区, 覆膜, 土壤水热, 土壤酶, 土壤氮