【摘要】 本文在小麦‖早春玉米/夏玉米超高产种植体系下,研究了套作夏玉米根系数量与活性的空间分布及变化规律,主要结果:(1)套作夏玉米于开花期达到最大根深160cm左右,且120～160cm深层根量持续增长至蜡熟末期。(2)根系数量呈上多下少的"T"型分布,0～20、20～80、80～120及120～160cm土层分别为根系高密度区、中密度区、低密度区和稀密度区。0～20、20～40及40～80cm土层根量密度大致于开花灌浆期达到最大值,之后呈下降趋势;80～120cm及120～160cm土层分别于灌浆期和蜡熟末期达最大;0～160cm整体根量密度以灌浆期为最大。(3)根系活性在土体中与数量相反呈倒"T"型分布。随生育进程推进,不同土层根系活性呈小→大→小变化,并且根系最高活性位点呈下移趋势,拔节期以20～40cm土层最高、大口期和开花期以80～120cm最高、灌浆期和蜡熟末期以120～160cm最高。0～160cm整体根系平均以大口期活性最高。(4)根系TTC还原总量在土体中呈上高下低的"T"型分布,根据TTC还原总量和总量密度高低,0～20、20～120和120～160cm土层分别为高量高密度区、中量中密度区和低量低密度区。从动态看,120cm以上各土层根系TTC还原总量及总量密度于花期达最大值,120～160cm深层土壤于灌浆期达最大值。0～160cm整体根系的TTC还原总量及总量密度?更多还原

【Abstract】 In the "winter wheat‖early spring maize/summer maize" cropping system, the vertical distribution and its change of root quantity and activity of the intercropped summer maize were studied The main results are as follows: ① The maximum rooting depth of the intercropped summer maize was about 160 cm and the root quantity in 120～160 cm soil layer continued to increase till the late waxmature stage ② From top to deep soil layers, the vertical distribution of root weight and root weight density shaped like a "T", and 0～20 cm, 20～80 cm, 80～120 cm and 120～160 cm could be classified, respectively, as high, mid, lower and thin root density layers The root density in the soil layers of 0～20 cm, 20～40 cm, and 40～80 cm reached its maximum, respectively, at flowering stage, and decreased afterwards; while that in the soil layers of 80～120 cm and 120～160 cm reached its maximum at milking or late waxmature stage The total (0～160 cm) root quantity and its density reached its peak at milking stage ③ Contrary to the quantity distribution, root activity (TTC reducing capacity) shaped like "⊥" from top to deep soil Peak root activities at jointing, male tetrad, milking, and late waxmature stage occurred in 20～40 cm, 80～120 cm, 120～160 cm soil layer, ie, the highest activity point moved deeper with the advance of growing stages The average root activity of 0～160 cm reached its top point at male tetrad stage ④ The root TTC reducing quantity and its density shaped like "T" on the vertical soil profile, and 0～20 cm, 20～120 cm, and 120～160 cm were classified as high, mid, and lower density layers respectively With the advance of growing stages, the root TTC reducing quantity and its density reached top at flowering stage in 0～120 cm, at milking stage in 120～160 cm The total (0～160 cm) root TTC reducing quantity and its density reached top at flowering stage更多还原