长江中游地区狗牙根和白三叶生产力对种间竞争的响应

The response of productivity of bermudagrass and white clover to inter-specific competition in the middle reaches of the Yangtze River

运用deWit(1960)的植物竞争试验方法,在大田条件下对狗牙根和白三叶单播及混播草地进行地上生物量动态及种间竞争的研究.结果表明:白三叶50%+狗牙根50%混播处理的地上生物量最高,与其他4个处理的地上生物量相比差异均极显著(P<0.01),单播白三叶处理的地上生物量最低.单播狗牙根地上生物量与绝对生长速率显著大于单播白三叶,狗牙根单混播生产力均在2005年8月最高.表明不同处理下,2种牧草表现为阶段性的资源共享和资源竞争关系,整个生育期内狗牙根的相对竞争力高于白三叶.

The deWit＇s test of plant competition was used to explore the response of productivity to inter-specific competition between two grass species（bermudagrass and white clover） in the midstream region of the Yangtze River.The results showed that treatment C（ratio of white clover to bermudagrass,1∶1） had the highest aboveground biomass in all treatments（P0.01）.The aboveground biomass of treatment A（monoculture of white clover） was the lowest.The aboveground biomass and the absolute growth rate of bermudagrass monoculture were higher than those of white clover.The bermudagrass monoculture showed the highest productivity in August,2005.Two species in different treatments had both symbiotic and competitive relationship in resources utilization model in different growth periods.The competitive ability of bermudagrass was higher than that of white clover throughout the growth season.