Comparison of Root Distribution Between Spreading-leaf and Upright-leaf Maize Cultivars in Songnen Plain

In a soil column culture and a field experiment, the comparison of root distribution of spreading-leaf and upright-leaf maize cultivars in Songnen Plain was studied. The results showed that there were differences in the root distribution of different maize cultivars. The maximum of root dry weight appears on the 15th and 30th day after silking for spreading-leaf and upright-leaf maize cultivar,respectively. Compared with spreading-leaf maize cultiver, the root dry weight of upright-leaf maize cultivar is highter by 12.2 percent. The vertical distribution of different maize cultivar roots is different. The root dry weight rate below 20 cm depth in spreading-leaf maize cultivar is less than 19 percent, whereas that in upright-leaf maize cultivar is more than 23 percent. Compared with spreading-leaf maize cultivar, the root dry weight rate below 40～100cm depth is higher by 43.3 percent. There are differences between the different maize cultivars in the horizontal distribution. The root systems of upright-leaf maize cultivar distribute tightly in horizon. The percentage of root dry weight of upright-leaf maize cultivar in a horizontal area (0～10 cm from the plant center) is higher than that in spreading-leaf maize cultivar by 9.6 percent. It is concluded that upright-leaf maize cultivar has many roots in deeper soil and it distributes tightly in horizon. Therefore, it is suitable for compact-planting. It is easier to acquire high yield for upright-leaf maize cultivar because it has good root distribution characteristics.