间套作条件下作物根系数量与活性的空间分布及变化规律研究 Ⅱ.间作早春玉米根系数量与活性的空间分布及变化规律  

Vertical Distribution and Its Change of Root Quantity & Activity of Crops in th e "Winter Wheat‖Early Spring Maize/Summer Maize" Cropping System Ⅱ.The Vertical Distribution and Its Changes of Root Quantity & Activity of the Early Spring Int

作　　者：赵秉强[1] 张福锁[2] 李增嘉[3] 李凤超[3] 张新春[3] 申加祥[3] 潘海军[3] 赵甲美[3] 尹玉波[3] 武传杰[3] 

机构地区：[1]中国农业科学院土壤肥料研究所,北京100081 [2]中国农业大学,北京100094 [3]山东农业大学,山东泰安271018

出　　处：《作物学报》2001年第6期974-979,共6页Acta Agronomica Sinica

基　　金：国家自然科学基金资助项目 (39870 5 2 4)

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 10 0cm左右 ,大口期 140 cm左右 ,乳熟期达到最大根深 160 cm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～ 2 0 cm为高密度层 ,2 0～ 4 0、 4 0～ 80 cm为中密度层 ,80～ 12 0 cm为低密度层 ,12 0～ 160 cm为稀密度层。根系相对稳定后 ,约有 75 %的根干重分布在 0～ 2 0 cm土层 ,85 %左右在 4 0 cm以上 ,95 %左右在 80 cm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 2 0～ 4 0cm根系活性较高 ,大口期 4 0 cm以下较高 ,乳熟期和成熟期以 80 cm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～ 2 0 cm为高量高密度区 ,2 0～ 80 cm为中量中密度区 ,80～ 12 0 cm为低量低密度区 ,12 0～ 160 cm为稀量稀密度区。 (6)成熟期 2In the 'winter wheat‖early spring maize/summer maize' cropping system , the vertical distribution and its change of root quantity & activity of the ea rly spring inter planted maize were studied. The main results are as follows: ① The maximum rooting depth was 100cm, 140cm and 160cm, respectively at jointing, male tetrad 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 t o high and then to low again. From top to deep soil layers, the vertical distrib ution of root weight and root weight density shaped like a ″T″, and 0~20 cm, 2 0~8 0 cm, 80~120 cm and 120~160 cm soil layers were categorized respectively into hi gh, 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 w ere respectively 75%, 85% and 95%. ③ The moisture content of fresh root increas ed 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 low er in the top soil layers and higher in deep layers, which shaped like a '⊥'. W ith 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 joint ing, male tetrad, milk grain & ripe stage occurred in 20~40cm, below 40 cm, and below 80 cm soil layer, respectively. ⑤ With the advance of growing st ages, the root TTC reducing quantity and its density also changed from low to hi gh and to low again, with the peak occurring at the male tetrad stage. 0~20 cm, 2 0~80 cm, 80~120 cm and 120~160 cm soil layers were classified respectively as hi gh, mid, lower and thin root TTC reducing density layers. ⑥ The root activity belo w 20 cm soil layers increased a little at the ripe stage, and the reason was not clear.

关 键 词：间套作 根系 早春玉米 数量 活性 空间分布 

分 类 号：S311[农业科学—作物栽培与耕作技术]