苣卖菜芽根在土壤耕层中分布的研究

THE DISTRIBUTION OF PERENNIAL SOWTHISTLE(SONCHUS BRACHYOTUS)ROOT IN PLOW HORIZON

对苣卖菜芽根在土壤耕层中的分布以及土壤耕作对其的影响进行了调查分析，发现首荬莱芽根在小麦田和玉米田９０％以上分布于０～１０ｃｍ耕层内，而大豆田苣荬莱芽根分布相对较深，８０％左右分布于０～１０ｃｍ耕层．土壤耕作次数增多，芽根变短，但对根量分布的影响小麦田和大豆田表现不同，小麦田只翻地处理，０～１０ｃｍ土层内根量显著减少，进一步耙地虽有回升，但也不及原茬，而大豆田翻地之后０～１０ｃｍ耕层根量超过原茬，而进一步把地后又降低至原茬之下．

The distribution of perennial sowthistle(Sonchus braehyotus)root in plow horizon andthe of influence tillage were inuestigated in this experiment.It was found that 90% roots distributed at the of 0～10 cm depth in wheat and corn field, while 80% in soybean field.The root tended to get shorter under more frequent tillage.The distribution of root caused by tillagc was different between wheat and soybean field Plowing significantly decreased the roots of the weed at the depth of 0～10 cm in soil in wheat field,while following harrouing increasea them a littie. However, in plowed soybean field there wer more roots at the same depth of soil than in unplowed field,after harrowing htey were deereascd to less than inunplowed field.