【作者】 赵秉强； 张福锁； 李增嘉； 李凤超； 张新春； 申加祥； 潘海军； 赵甲美；

【Author】 Zhao bingqiang Zhang Fusuo (China Agricultural University, Beijing 100094)Li Zengjia Li Fengchao Zhang xinchun Shen Jiaxiang Pan Haijun Zhao Jiamei(Shandong Agricultural University, Taian, 271018)

【机构】 中国农业大学； 山东农业大学；

【摘要】 本文在冬小麦//早春玉米/夏玉米条件下,研究了麦田间作地膜覆盖早春播种玉米(简称早春玉米)根系数量与活性的空间分布及变化规律,主要结果:①间作地膜覆盖早春玉米拔节期根深100cm左右,大口期140cm左右,乳熟期达到最大根深160cm左右。②随生育进程推进,根量与根重密度基本呈小→大→小变化;根系数量及重量密度在垂直土体中呈“T”型分布,0～20cm为高密度层,20～40、40～80cm为中密度层,80～120cm为低密度层,120～160cm为稀密度层。根系相对稳定后,约有75％的根干重分布在0～20cm土层,85％左右在40cm以上,95％左右在80cm以上。③根系含水率在垂直空间呈上低下高趋势,随生育期推进,含水率呈下降趋势。④根系活性与根量相反呈倒“T”型分布,根系活性随生育进程推进,呈减低趋势,且活力高位点又呈下移变化,拔节期20～40cm根系活性较高,大口期40cm以下较高,乳熟期和成熟期以80cm以下较高。⑤根系TTC还原总量及总量密度随生育进程推进呈低→高→低变化,以大口期为高。上下又呈“T”型分布,0～20cm为高量高密度区,20～80cm为中量中密度区,80～120cm为低量低密度区,120～160cm为稀量稀密度区。⑥成熟期20cm以下土层根系活性具有反弹上升现象。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 & aclivity of the early spring inter-planted maize were studied. The main results are as follows: (1)The maximum rooting depth was 100 cm, 140 cm and 160 cm, respectively at jointing, male lenad and milk grain stage. (2)The root weight and root weight density at different soil layers changed, with the advance of the growth stages, from low to high and then to low again, 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 soil layers were categorized respectively into high, mid, lower and thin root density layers. After flowering, the percentage of the dry root weight of 0- 20 cm, 0-40 cm, 0 - 80 cm soil layers to the total of 0 - 160 cm were respectively 75% , 85% and 95% . (3)The moisture content of fresh root increased from top to deep soil layers and decreased with the advance of growing stages.(4)Contrary to the quantity, the root activity (TTC reducing capacity) was lower in the top soil layers and higher in deep layers, which shaped like a "T" . With the growth stages advance, the root activity decreased, and the highest root activity point on vertical soil moved deeper, i.e., the highest points of jointing, male tetrad, flowing and milk grain & ripe stage occurred in 20 - 40 cm, below 40 cm, and below 80 cm soil layer, respectively. (5)With the advance of growing stages, the root TTC reducing quantity and its density also changed from low to high and to low again, with the peak occurring at the male tetrad stage.0 - 20 cm, 20 - 80cm, 80 - 120cm and 120 - 160 cm soil layers were classified respectively as high, mid, lower and thin root TTC reducing density layers.(6)The root activity below 20 cm soil layers increased a little at the rpie stage , and the reason was not clear.更多还原