关键词: 豆科牧草, 禾本科牧草, 杂草, 混播, 重要值, 群落稳定性

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