3种牧草不同搭配方式对胜红蓟的替代控制

Replacement Control Effects of Three Pasture Species Combinations on Ageratum conyzoides

研究3种牧草不同搭配方式对胜红蓟的替代控制效果,为入侵杂草胜红蓟的防控提供植物种和替代控制方法。在田间条件下,通过将白三叶、杂交甜高粱、杂交狼尾草3种牧草两两等比例搭配后与胜红蓟按2∶1混种,建立3种不同的替代控制方式,动态监测各群落(种群)植物、土壤微生物指标,评价3种牧草两两等比例搭配对胜红蓟的替代控制效果。结果表明:白三叶、杂交甜高粱等比例搭配对胜红蓟进行替代控制时,2种牧草株高严重受阻,牧草相对盖度占优,Simpson指数和Shannon-wiener指数均变大,胜红蓟重要值变小,土壤真菌增多,细菌、放线菌减少;白三叶、杂交狼尾草等比例搭配对胜红蓟进行替代控制时,2种牧草株高不受阻,牧草相对盖度占优,Simpson指数变大,Shannon-wiener指数变小,胜红蓟重要值变小,土壤真菌增多,细菌、放线菌减少;杂交狼尾草和杂交甜高粱等比例搭配对胜红蓟进行替代控制时,杂交狼尾草株高不受阻,但杂交甜高粱株高严重受阻,牧草相对盖度占优,Simpson指数变小,Shannon-wiener指数变大,胜红蓟重要值变小,土壤细菌增多,真菌、放线菌减少。总体来看,白三叶和杂交狼尾草可以等比例搭配作为胜红蓟替代控制材料,且替代控制效果较好;白三叶和杂交甜高粱、杂交甜高粱和杂交狼尾草不宜等比例搭配作为胜红蓟的替代控制材料。

Three pasture species were evaluated as a means to restore fields infested with the invasive weed Ageratum conyzoides. Pairs of the pastures Trifolium repens, Sorghum bicolor and Pennisetum americanum x P. purpureum were grown in mixture with the target plant A. conyzoides at 2 ： 1 proportions. Plant population and community indexes were monitored dynamically to evaluate the replacement ability of the pastures over A. conyzoides. In the model composed by A. conyzoides, T. repens and S. bicolor the height of the two pasture species was severely reduced, relative coverages were dom- inant, community Simpson and Shannon -wiener indexes became larger, the importance value of A. conyzoides was reduced and microbial indicators were affected with fungi in- creasing and both bacteria and actinomyces were re- duced. When the model included A. conyzoides, T. re- pens and P. × P. purpureum, height of the pastures was not reduced, relative coverage was domi- nant, community Simpson indexes turned larger but Shannon - wiener indexes became smaller, and the im- portance value of A. conyzoides turned smaller, fungi were reduced and both bacteria and actinomyces increased. The third model included A. conyzoides, S. bicolor and P. americanum × P. purpureum. In this case, height of P. americanum × P. purpureum was not diminished but that S. bicolor of was severely decreased, relative coverage was dominant, community Simpson indexes decreased but Shannon -wiener indexes increased, and the importance value of A. conyzoides decreased, bacteria increased, and both torulae and actinomy- ces were reduced Overall, the combination of T. repens and P. americanum ~ P. purpureum was suitable to replace and control A. conyzoides