松嫩平原平展型和紧凑型玉米品种根系分布特征

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

采用土柱模拟栽培法与大田试验相结合的方法 ,对松嫩平原不同株型玉米的根系分布特征进行了比较。研究发现 ,平展型玉米和紧凑型玉米根干重最大值出现的时期不同 ,二者根干重分别在吐丝后15d和吐丝后30d时达到最大值。成熟时紧凑型玉米根干重比平展型高12.2 %。二者根系垂直分布有明显的差异 ,在20cm以下的根干重比率 ,平展型玉米在19 %以下 ,而紧凑型玉米高于23%。紧凑型玉米的深层根量较多 ,在深40～100cm土层内根干重比率比平展型高42.3%。二者的根系水平分布也不同 ,紧凑型玉米根系水平分布较集中 ,在距植株0～10cm水平范围内 ,根系分布比率比平展型玉米高9.6 %。紧凑型玉米土壤深层根量较多 ,水平分布集中 ,耐密植 ,是易获得高产的重要原因之一。

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.