Abstract: In order to investigate the effects of sowing species on productivity and stability of artificial grassland communities,a complete randomized design experiment was conducted with three monoculture sowing (Medicago sativa,CK1;Bromus inermis,CK2;Elymus nutans,CK3) and four mixed sowing patterns (Medicago sativa + Bromus inermis,A;Medicago sativa + Elymus nutans,B;Bromus inermis + Elymus nutans,C;Medicago sativa + Bromus inermis + Elymus nutans,D). The forage biomass,weed biomass,weed proportion,weed species and important value of artificial grasslands were measured for three consecutive years. We analyzed the annual and seasonal dynamics of forage productivity and the lays of weeds occurrences and changes in the paper,to provide theoretical basis for the successful management on the establishment and sustainable utilization of artificial grassland. The results showed that the mixed sowing forage species of Medicago sativa and Bromus inermis had the highest forage yield and inhibited the invasion of weeds. The forage yield was the lowest in the first year,and then increased year by year. The percentage of weeds was 46%～85% in the first year since sowing with the major annual weeds of Chenopodium glaucum and Chenopodium aristatum,when was the critical time for weed control. In the 2nd year since sowing,the percentage of weeds was relatively small which exited in the concomitant position in the artificial grassland;but the weeds were still serious in summer and autumn,when the weeds should be controlled properly. In the third year since sowing,the proportion of weeds was 3%～28%,with the most of which were perennial weeds,such as Gernium wilfordii Maxim,Potentilla bifurca,P. supina,Convolvulus arvensi and Plantago asiatica,which had a little effect on the total biomass accumulation of the artificial grasslands and weed control should not be set into the principal operations in the management of the artificial grasslands.

Key words: Legumes, Gramineous forage, Weeds, Mixed sowing, Important value, Community stability

摘要： 以紫花苜蓿(Medicago sativa)、无芒雀麦(Bromus inermis)、披碱草(Elymus nutans)单播及紫花苜蓿+无芒雀麦、紫花苜蓿+披碱草、无芒雀麦+披碱草、紫花苜蓿+无芒雀麦+披碱草为处理，采用完全随机设计试验，连续3年测定各处理的牧草生物量、杂草生物量、牧杂草占比、杂草种类及重要值，分析人工草地生物量动态变化及杂草发生、变化规律,为人工草地成功建植和可持续利用提供理论依据。结果表明：紫花苜蓿和无芒雀麦混播处理的牧草产量最高，并且对杂草入侵有较好的抑制效果，年际间，建植第1年牧草产量最低，随后两年牧草产量逐年增加。建植第一年杂草占比较大，分别达到46%～85%，以灰绿藜(Chenopodium glaucum)、刺藜(Chenopodium aristatum)等一年生杂草为主，为杂草控制关键期。第2年春夏季杂草占比较小，处于伴生地位，夏秋季杂草依然严重，可适当控制。第3年杂草占比小，占比为3%～28%,以老鹳草(Gernium wilfordii)、二裂委陵菜(Potentilla bifurca)、朝天委陵菜(Potentilla supina)、田旋花(Convolvulus arvensis)和车前(Plantago asiatica)等多年生杂草为主，但对栽培牧草生物量积累影响较小，可不把杂草控制作为草地管理重点。

关键词: 豆科牧草, 禾本科牧草, 杂草, 混播, 重要值, 群落稳定性