兰州引黄灌区玉米田杂草群落及生态位研究

对兰州引黄灌区玉米田杂草进行了研究,初步了解了其杂草种类和杂草种群的消长动态。主要杂草有打碗花、田旋花、藜、刺儿菜、荠菜、稗草、马齿苋、反枝苋、狗尾草。主要杂草的干重为藜、反枝苋、稗草分别列第1、第2和第3位。生态位的研究结果表明,藜的时间、水平、垂直生态位宽度值最高,分别为0.952 6,0.971 8,0.937 9,其危害最大;其次为反枝苋和稗草。藜、反枝苋和稗草为优势种群,与玉米存在时间、水平、垂直空间的竞争激烈,并且这3种杂草的生态位重叠值也最大,因此在使用一种除草剂时,可能会导致另两种杂草的发生与蔓延。马齿苋尽管数量最多,但其在垂直方位的生态位宽度值最小,对玉米影响小,处于劣势。除草处理各经济性状指标值均较不除草对照高,其折合产量为10 111.11 kg/hm2,较不除草处理增产36.19%。

Weed communities and the eco-niche in Zea mays fields in the Yellow river valley of Lanzhou

An investigation of the species,growth and withering, and the time,horizontal and vertical niche of the main weeds in maize fields of the Yellow River valley of Lanzhou showed that Calystegia hederacea,Convolvulus arvensis,Chenopodium album,Cephalanoplos segetum,Capsella bursa-pastoris,Echinochloa crusgalli,Portulaca oleracea,Amaranthus retroflexus and Setaria viridis were the main weeds plant species.The dry weight per 1 m2 of C.album,A.retroflexus,and E.crusgalli were the highest,second and third respectively.The results of eco-niche research indicated that based on the calculation of time,horizontal and vertical breadth of the weed community,C.album was most important weed followed by A.retroflexus and E.crusgalli.Their niches overlapped extensively.The yields following weed control treatment were 36.19% higher than that of the control.