扩行缩株对夏玉米群体冠层结构及产量的影响

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丁相鹏^,, 白晶, 张春雨, 张吉旺, 刘鹏, 任佰朝, 赵斌^,山东农业大学农学院/作物生物学国家重点实验室,山东泰安 271018

Effects of Line-Spacing Expansion and Row-Spacing Shrinkage on Population Structure and Yield of Summer Maize

DING XiangPeng^,, BAI Jing, ZHANG ChunYu, ZHANG JiWang, LIU Peng, REN BaiZhao, ZHAO Bin^,College of Agronomy, Shandong Agricultural Univercity/State Key Laboratory of Crop Biology, Tai’an 271018, Shandong

通讯作者: 赵斌,E-mail： zhaobin@sdau.edu.cn

责任编辑: 杨鑫浩
收稿日期:2020-05-11接受日期:2020-07-13网络出版日期:2020-10-01

基金资助:

国家重点研发计划.2018YFD0300603
国家重点研发计划.2017YFD0301001

Received:2020-05-11Accepted:2020-07-13Online:2020-10-01
作者简介 About authors
丁相鹏,E-mail： 1751592368@qq.com。

摘要
【目的】探明不同密度下扩行缩株（扩行距缩株距）栽培模式对黄淮海夏玉米产量和群体结构的调控效应。【方法】2018—2019年以密植高产玉米品种郑单958为试验材料,设置3种行距,即60 cm（B1）、80 cm（B2）、100 cm（B3）等行距;2个种植密度,即67 500株/hm²（D1）和82 500株/hm²（D2）,采用裂区设计形成不同的栽培模式。【结果】与D1密度相比,D2密度能显著提高夏玉米群体叶面积和光合势,改善群体的光能利用,增加群体的干物质积累量,促进产量的增加。不同种植密度条件下,扩行缩株对夏玉米群体结构的影响存在差异。在67 500株/hm²密度下,扩行缩株对产量的影响不显著,在82 500株/hm²密度下,B2处理较B1和B3处理2年平均增产9.45%和11.48%,主要是由于行粒数增加引起的穗粒数增加。在此密度下,B2处理较B1处理显著提高花后群体叶面积指数（LAI）,显著延缓中下部叶片衰老,增加花后夏玉米群体光合势,茎叶夹角增大,叶向值减小,穗位叶层和底层透光率明显增加,消光系数减小,花后干物质积累量增加,花后干物质转移量降低。表明高密度条件下,80 cm扩行的等行距模式有利于构建高效的光合群体结构,延缓叶片衰老,增加夏玉米群体干物质生产与积累,从而提高产量。【结论】黄淮海平原夏玉米通过增加种植密度并适当扩行缩株可实现光能资源高效利用和产量协同提高,本试验条件下,推荐82 500 株/hm²密度搭配80 cm等行距种植模式。
关键词： 扩行缩株;种植密度;群体冠层结构;夏玉米;产量

Abstract

【Objective】 The aim of this study was to explore the regulatory effects of expanding and shrinking cultivation models under different densities on the yield and population structure of Huang-Huai-Hai summer maize. 【Method】 The high yield maize variety Zhengdan958 was used as experimental material, three kinds of row spacing treatments, such as 60 cm (B1), 80 cm (B2), and 100 cm (B3), and two planting densities of 67 500 plants/hm²and 82 500 plants/hm², were used to form different cultivation patterns through split zone design in 2018 and 2019. 【Result】 Compared with D1 density, D2 density could significantly increase the population leaf area and photosynthetic potential, improve the light energy utilization of the population, increase the dry matter accumulation of the population, and promote the increase of yield. Under the condition of different planting density, the effect of expansion and shrinkage on population structure was different. Under the density of 67 500 plants/hm², the effect of expansion and shrinkage on the yield was not significant. Under the density of 82 500 plants/hm², B2 treatment increased the yield by increasing the number of grains per row and 1000-grain weight, which was 9.45% and 11.48% higher than that of B1 and B3 treatments, respectively. B2 treatment significantly increased the population leaf area index (LAI), delayed the senescence of the middle and lower leaves, increased the photosynthetic potential of the population after anthesis, increased the angle between stems and leaves, and decreased the leaf orientation value. The light transmittance of leaf layer and bottom layer in panicle position increased significantly, the extinction coefficient decreased, the dry matter accumulation increased after anthesis, and the dry matter transfer decreased after anthesis. The results showed that under the condition of high density, the equal row spacing model of 80 cm expansion was beneficial to build an efficient photosynthetic population structure, delay leaf senescence, improve the photosynthetic performance of the population, increase the production and accumulation of dry matter of the population, and thus increase the yield. 【Conclusion】 The high-yield cultivation of summer maize in Huang-Huai-Hai Plain can achieve efficient utilization of light energy and synergistic increase in yield by increasing planting density and appropriate expansion and shrinking of plants. Under the experimental conditions, a planting pattern of 82 500 plants/hm² with a density of 80 cm is recommended.

Keywords：expanding and shrinking plant;planting density;canopy structure;summer maize;yield

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本文引用格式
丁相鹏, 白晶, 张春雨, 张吉旺, 刘鹏, 任佰朝, 赵斌. 扩行缩株对夏玉米群体冠层结构及产量的影响[J]. 中国农业科学, 2020, 53(19): 3915-3927 doi:10.3864/j.issn.0578-1752.2020.19.006
DING XiangPeng, BAI Jing, ZHANG ChunYu, ZHANG JiWang, LIU Peng, REN BaiZhao, ZHAO Bin. Effects of Line-Spacing Expansion and Row-Spacing Shrinkage on Population Structure and Yield of Summer Maize[J]. Scientia Acricultura Sinica, 2020, 53(19): 3915-3927 doi:10.3864/j.issn.0578-1752.2020.19.006

0 引言

【研究意义】玉米是重要的粮食作物,对我国粮食安全至关重要^[1]。随着世界人口增加,预计到2050年,全球粮食需求将增长100%—110%^[2]。在不增加耕地面积的前提下,要达到这个目标需要依赖单位土地面积上产量的增加^[3,4,5]。密植是提高玉米单产的重要栽培措施之一^[1,6]。当种植密度过高时会导致冠层透光不良,增加倒伏风险,不利于产量提高^[1,5,7-8]。同时面对气候变化尤其是光辐射下降的不利影响,更加迫切需要塑造良好群体结构来改善冠层内光分布^[9,10],进而实现夏玉米生育期内有限光能资源的高效利用以及产量的提高,对夏玉米的高产栽培具有重要意义。【前人研究进展】2009年以后黄淮海夏玉米区密度稳定在6.22×10⁴株/hm^2[11],在现有品种情况下,进一步发挥产量潜力,增加种植密度是未来发展的趋势。而高密度易造成群体内光分布不合理^[12],玉米冠层内超过70%的叶片被相互遮挡,这些叶片大约吸收冠层光吸收总量30%的光能,对冠层总光合的贡献占47%左右^[13],要进一步提高作物产量,改善冠层内的光分布显得尤为重要。前人研究表明,通过在玉米不同营养生长阶段喷施化学调控剂^[14]或去除玉米顶部叶片^[15]等措施均起到改善群体光分布增加产量的目的,但操作起来费时费力。而行距配置操作相对方便且对于优化群体冠层内光资源的分配效果显著,随密度增加行株距配置的增产作用更加明显^[16]。研究表明,高密度下宽窄行种植可扩大光合面积,改善群体冠层结构,提高群体光合特性,更好地协调玉米群体和个体的关系,提高玉米群体的光能利用率^[8,16-17]。而苌建峰等^[18]认为高密度下等行距处理能够改善群体内小气候,提高中下部的光能截获率,增强抗逆性,更有利于产量的提高。此外,刘永忠等^[19]研究表明,高密度下平均行距相同的宽窄行和等行距处理均有利于提高叶面积指数,群体光能辐射截获量,从而获得较高产量。可见种植习惯与自然环境的差异,导致行株距配置研究结果并不一致。因此,高密度条件下选用适宜行株距配置来塑造合理的群体冠层结构,更有利于群体光分布的合理性进而增加产量。【本研究切入点】前人在宽窄行或大小行种植模式与密度的互作中对冠层光分布、光合性能、产量构成等方面研究较多^{[16,17,18,19]},而结合区域光资源特点,通过采用扩行距缩株距（扩行缩株）以协调夏玉米群体冠层结构、调控光分布和群体物质生产,实现光能高效利用与产量协同提高的研究鲜见报道。【拟解决的关键问题】本文在不同密度下,研究扩行缩株模式的群体冠层结构、不同层次光能利用和产量形成与黄淮海夏玉米区光资源的匹配关系,明确扩行缩株和密度对夏玉米群体冠层结构和产量形成的调控机理,以优化玉米种植区域布局,为推动玉米产量进一步提高提供理论依据与技术途径。

1 材料与方法

1.1 试验地状况

本试验于2018—2019年在山东农业大学黄淮海区域玉米技术创新中心（36.09° N,117.09° E）进行,地处黄淮海平原,属于半湿润暖温带大陆性季风气候区。根据2018年测定结果,试验土壤为棕壤土,耕层0—20 cm土壤pH 6.1,有机质10.5 g·kg^-1、全氮0.8 g·kg^-1、碱解氮84.4 mg·kg^-1、速效磷35.2 mg·kg^-1、速效钾81.8 mg·kg^-1,土壤田间持水量为21.1%,土壤容重1.5 g·cm^-3。

1.2 试验设计

试验品种为郑单958（ZD958）,采用裂区设计,主区为3种行距处理,即60 cm（B1）、80 cm（B2）、100 cm（B3）等行距;副区为2个种植密度,即67 500株/hm²（D1）和82 500株/hm²（D2）。由密度定株距,分别为25、19、15 cm和20、15、12 cm,共6个处理。每个处理种植5行,行长10 m,重复3次。2018和2019年均在6月8日播种,施肥情况均为105 kg P₂O₅·hm^-2,180 kg K₂O·hm^-2,240 kg N·hm^-2。P₂O₅、K₂O和50%氮肥全部底施,50%氮肥以开沟形式于拔节期施入;其他按照高产田进行田间管理。

1.3 测定项目及方法

1.3.1 植株干物质积累量分别于吐丝期（R1）和成熟期（R6）取样,每个处理取样5株。植株分为叶片、茎杆、雄穗、苞叶和籽粒,分别于105℃杀青30 min,80℃烘干至恒重。并计算吐丝后干物质积累量和吐丝后生物量对籽粒贡献率^[20]。

花后干物质积累量（t·hm^-2）=成熟期地上部干物质积累量-吐丝期地上部干物质积累量;

干物质转移量（t·hm^-2）=吐丝期地上部干物质积累量-成熟期地上部营养器官干物质积累量;

干物质转移对籽粒贡献率（%）=（干物质转移量/籽粒干重）×100。

1.3.2 叶面积指数（LAI）于大喇叭口期（V12）、吐丝期（R1）、乳熟期（R3）、成熟期（R6）选择生长发育一致、叶片无病斑和破损的植株测定,重复5次。单叶叶面积 = 长×宽×0.75,LAI = 单株叶面积×单位土地面积内株数/单位土地面积。光合势LAD（m²·d·m^-2）= [(L₁+L₂)/2]×(t₂-t₁),L₂、L₁分别为t₂、t₁时间的叶面积^[21]。

1.3.3 群体光分布于吐丝期和灌浆期选择晴朗无云天气,在9：00—11：00采用SunScan冠层分析仪（Delta,UK）测定。在行间按对角线方式,测定植株底层（距地面15 cm）、穗位叶层光合有效辐射量（TPAR）和冠层顶部入射光合有效辐射量（IPAR）。计算冠层光合有效辐射透过率：PAR透过率=TPAR/IPAR;消光系数（K）用对数函数进行计算^[5]：K=$\frac{-\text{ln}(\text{TPAR/IPAR})}{\text{LAI}}$。

1.3.4 农艺性状考察在吐丝期用直尺测定植株株高、穗位高,穗位系数（%）=穗高/株高×100;在乳熟期的第1节间用数字测径仪测量了茎的最大直径（A）和最小直径（a）,随机测定10株。茎秆面积（cm²）=$\frac{\text{A}(\text{mm})}{2}\times \frac{\text{a}(\text{mm})}{\text{2}}\times \frac{\text{ }\!\!\pi\!\!\text{ }}{100}$^[22],π为圆周率。

在吐丝期选取有代表性植株10株,用米尺测定棒三叶的叶长和叶基至叶片最高点的距离,用量角器测定茎叶夹角（即茎秆与叶脉的上方夹角）,并计算叶向值^[23]：

LOV=$\sum\limits_{\text{i}=\text{1}}^{\text{n}}{\theta \text{(}{{\text{L}}_{\text{f}}}\text{/L)/n}}$

式中,θ为叶倾角,L_f为叶基部到叶片最高处的长度, L为叶片全长,n为叶片数。

1.3.5 产量测定玉米成熟期（乳线消失,黑层出现）收获,大田各小区分别收获中间3行用于测产,然后随机取30个果穗,用于考种,主要测定穗长、秃顶长、穗行数、行粒数、千粒重,以14%籽粒含水量计算产量。

1.4 统计分析

采用Microsoft Excel 2013处理数据,用SPSS 21.0软件统计分析,用Sigmaplot 10.0（Systat Software,San Jose,CA）作图。

2 结果

2.1 扩行缩株对夏玉米产量及构成因素的影响

年份、密度和行距及密度与行距的交互作用对夏玉米秃尖长、行粒数、穗行数和产量有显著影响（表1）。D2较D1产量2年分别显著提高13.86%（2018年）和15.37%（2019年）（P<0.05）。D1密度下,各处理间产量无显著差异。D2密度下,B2处理产量显著高于B1和B3处理（P<0.05）,2年均值提高了9.45%和11.28%,而B1和B3处理产量差异不显著。同时B2处理较B1和B3处理行粒数和穗粒数也显著增加（除2018年B1和B2处理行粒数差异不显著）,千粒重表现为B2处理高于其他处理。可以看出,D2密度下B2处理产量最高,主要是行粒数增加引起的穗粒数显著增加。

Table 1
表1
表1扩行缩株对夏玉米产量及构成因素的影响
Table 1Effects of line-spacing expansion and row-spacing shrinkage on yield and components of summer maize

年份 Year	密度 Density	行距 Row space	穗长 Ear length (cm)	秃顶长 Bald tip length (cm)	穗行数 Number of lines per ear	行粒数 Number of kernels per line	穗粒数 Spike grain number	千粒重 Weight of 1000-kernels (g)	产量 Yield (t·hm^-2)
2018	D1	B1	17.18a	0.13c	15.42a	33.86a	522.12a	316.28a	10.89c
		B2	17.22a	0.06f	15.53a	33.44a	519.32a	318.47a	10.79c
		B3	17.27a	0.11e	15.56a	32.62bc	507.57ab	315.72ab	10.56c
		平均值Average	17.22	0.10	15.50a	33.31	516.34	316.82	10.75
	D2	B1	16.95a	0.17b	15.24a	31.56c	480.97bc	309.08bc	11.99b
		B2	16.95a	0.10d	15.36a	33.25ab	510.72a	314.92ab	13.07a
		B3	16.84a	0.23a	15.17a	31.23c	473.76c	304.75c	11.66b
		平均值 Average	16.91	0.17	15.26a	32.01	488.48	309.58	12.24
2019	D1	B1	16.84ab	0.23d	15.71a	34.02a	534.45a	312.24ab	10.99c
		B2	17.04ab	0.28c	15.77a	34.57a	545.17a	315.18a	11.16c
		B3	17.58a	0.16e	15.69a	33.92a	532.20a	314.40ab	11.02c
		平均值 Average	17.15	0.22	15.72a	34.17	537.28	313.94	11.06
	D2	B1	16.59b	0.48a	15.61a	31.95b	498.76b	305.04c	12.41b
		B2	16.85ab	0.30b	15.67a	34.42a	539.34a	310.00abc	13.63a
		B3	16.71ab	0.31b	15.72a	31.22b	490.78b	308.20bc	12.33b
		平均值 Average	16.68	0.36	15.67a	32.53	509.63	307.75	12.79
	变异来源Sources of variation	年份 Year (Y)	NS	**	NS	*	**	NS	**
		密度 Density (D)	*	**	NS	**	**	*	**
		行距 Race space (R)	NS	**	NS	**	**	*	**
		年份×密度 Y×D	NS	**	NS	NS	NS	NS	NS
		年份×行距 Y×R	NS	**	NS	NS	NS	NS	NS
		密度×行距 D×R	NS	**	NS	**	*	NS	**
		年份×密度×行距 Y×D×R	NS	**	NS	NS	NS	NS	NS

D1and D2 represent the densities of 67 500, 82 500 plants/hm², respectively; B1, B2, and B3 represent the row spacings of 60, 80, 100 cm, respectively. The values in the same character were marked with different letters to indicate that there were significant differences in different row spacing treatments under the different densities in the same year (P<0.05). NS, *, ** indicate non-significant or significant at P<0.05 or P<0.01, respectively. The same as below
D1、D2分别表示种植密度为67 500、82 500株/hm²。B1、B2、B3分别表示行距为60、80、100 cm。同一性状中的数值标以不同字母表示在同一年度不同密度下不同行距配置处理在P<0.05水平上差异显著。NS、*和**分别表示无显著性差异及在0.05和0.01水平上差异显著。下同

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2.2 扩行缩株对夏玉米LAI的影响

2.2.1 LAI变化动态 D2较D1叶面积指数显著提高,2种密度下叶面积指数均随生育期推进呈单峰曲线变化,各处理均在吐丝期叶面积指数达到最大值,之后迅速下降,2年趋势相同（图1）。从开花期到完熟期,D2和D1的LAI均值分别显著下降了39.3%、44.0%（2018年）和37.7%、40.6%（2019年）（P<0.05）。表明D2较D1叶面积指数显著增大,但后期群体内竞争加剧,叶片衰老加快。

图1

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图1扩行缩株对夏玉米叶面积指数的影响

V12为大喇叭口期,R1为吐丝期,R3为乳熟期,R6为成熟期。下同
Fig. 1Effects of line-spacing expansion and row-spacing shrinkage on LAI of summer maize

V12: Trumpeting stage; R1: Silking stage; R3: Milking stage; R6: Maturity stage. The same as below

不同密度下扩行缩株处理对群体LAI影响不同。在D1密度下,各行距处理间总体差异均不显著。D2密度下,在吐丝期到成熟期,B2处理叶面积指数总体高于B1和B3处理;从乳熟期到成熟期B2处理叶面积指数显著高于B1处理,而B3处理与B1处理差异不显著。可以看出,适当扩行缩株种植模式有利于延缓生育后期叶片衰老。相关分析发现,花后叶面积与产量呈正相关（0.858—0.902）,因此,B2处理在高密度条件下可提高叶面积指数,增大群体光合绿叶面积,延缓花后叶片的衰老,更有利于产量提高。

2.3 不同叶层LAI变化动态

年份、密度和行距对棒三叶及其以下叶片LAI影响达极显著水平（表2）。不同处理各叶层LAI均为棒三叶以下>棒三叶>棒三叶以上。在吐丝期,D2棒三叶及其以下叶片LAI显著高于D1;乳熟期D2各叶层叶片LAI显著高于D1。从吐丝期到乳熟期,相比于棒三叶及以上叶片降低幅度,棒三叶以下叶片LAI降低幅度最大,表明D2较D1对下部的叶片影响较大。

Table 2
表2
表2扩行缩株对夏玉米各叶层叶面积指数影响
Table 2Effects of line-spacing expansion and row-spacing shrinkage on leaf area index of each layer of summer maize

年份 Year	密度 Density	行距 Row space	棒三叶以上Above three-ear leaves		棒三叶Three-ear leaves		棒三叶以下Under three-ear leaves
年份 Year	密度 Density	行距 Row space	吐丝期Silking	乳熟期Milking	吐丝期Silking	乳熟期Milking	吐丝期Silking	乳熟期Milking
2018	D1	B1	1.30b	1.22d	1.45c	1.42d	2.59d	2.24d
		B2	1.33b	1.26cd	1.48c	1.38de	2.76c	2.36c
		B3	1.33b	1.27c	1.39d	1.34e	2.47e	2.26d
		平均值Average	1.32	1.25	1.44	1.38	2.61	2.29
	D2	B1	1.52a	1.48a	1.74b	1.72b	3.15a	2.48b
		B2	1.48a	1.41b	1.81a	1.77a	3.22a	2.74a
		B3	1.49a	1.40b	1.70b	1.65c	2.97b	2.66a
		平均值Average	1.50	1.43	1.75	1.71	3.11	2.63
2019	D1	B1	1.41bc	1.33c	1.72b	1.70c	2.23d	1.71d
		B2	1.42bc	1.32cd	1.73b	1.71c	2.31d	1.73d
		B3	1.39c	1.28d	1.70b	1.67c	2.23d	1.71d
		平均值Average	1.41	1.31	1.72	1.69	2.26	1.72
	D2	B1	1.49a	1.39b	1.88b	1.85b	2.71c	2.02c
		B2	1.46ab	1.44a	1.94a	1.92a	2.85a	2.31a
		B3	1.45ab	1.40ab	1.89b	1.88ab	2.77b	2.19b
		平均值Average	1.47	1.41	1.90	1.88	2.78	2.17
	变异来源 Sources of variation	年份 Year (Y)	**	*	**	**	**	**
		密度 Density (D)	**	**	**	**	**	**
		行距 Race space (R)	NS	NS	**	**	**	**
		年份×密度Y×D	**	**	**	**	NS	**
		年份×行距Y×R	NS	NS	NS	*	**	NS
		密度×行距D×R	NS	NS	NS	*	NS	**
		年份×密度×行距 Y×D×R	NS	**	NS	NS	NS	NS

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在D1密度下,各处理对不同叶层LAI的影响总体差异不显著（除2018年棒三叶以下叶）,说明低密度下,B1处理冠层结构布局相对合理,通过扩行缩株模式来进一步优化群体冠层结构效果并不显著。2018年在吐丝期,D2密度下B1和B2处理棒三叶以下叶无显著差异,两者较B3处理均显著增加;2019年吐丝期B2处理显著高于B1和B2处理;而乳熟期棒三叶以下叶B2处理显著高于B1处理,2年均值增加了12.43%。此外,D2密度下B2处理较B1和B3处理棒三叶LAI在吐丝期和乳熟期均显著增加（除2019年B2和B3处理）。可见,在高密度下B2处理通过显著增加棒三叶及以下叶片叶面积,延缓了生育后期中下部叶片的衰老,尤其是下部叶片,促进产量提高。

2.4 群体光合势（LAD）

由表3可知,年份、密度和行距对吐丝后光合势和总光合势影响极显著（P<0.01）。D2较D1各生育阶段群体LAD均显著增加。D1密度下各处理总体无显著差异（除2018年吐丝到乳熟阶段B2和B3处理差异显著）。D2密度下,乳熟期到成熟期光合势以及吐丝后总光合势B2处理均显著高于B1和B3处理,B2处理总LAD较B1处理显著增加3.28%（2018年）和4.56%（2019年）（P<0.05）;而B3处理总LAD较B1处理无显著差异。可见,D2密度下B2处理更有利于吐丝后LAD的累积,这对于促进花后干物质的积累起到积极作用。

Table 3
表3
表3扩行缩株对夏玉米群体光合势的影响
Table 3Effects of line-spacing expansion and row-spacing shrinkage on LAD of summer maize population

年份 Year	密度 Density	行距 Row space	吐丝前光合势 LAD in pre-anthesis (m²·d·m^-2)			吐丝后光合势 LAD in post-anthesis (m²·d·m^-2)			总LAD Total LAD (m²·d·m^-2)
年份 Year	密度 Density	行距 Row space	VE-V12	V12-R1	Total	R1-R3	R3-R6	Total	总LAD Total LAD (m²·d·m^-2)
2018	D1	B1	65.76b	93.38c	159.14b	148.37cd	118.62c	267.00c	426.14c
		B2	67.63b	95.51c	163.15b	151.39c	118.37c	269.75c	432.90c
		B3	67.09b	92.50c	159.59b	145.64d	117.31c	262.95c	422.54c
		平均值Average	66.83	93.80	160.63	148.47	118.10	266.57	427.20
	D2	B1	80.75a	113.06ab	193.81a	175.40ab	131.51b	306.91b	500.73b
		B2	81.64a	114.54a	196.18a	180.30a	140.68a	320.98a	517.16a
		B3	80.61a	110.50b	191.11a	172.45b	134.11b	306.57b	497.68b
		平均值Average	81.00	112.70	193.70	176.05	135.44	311.49	505.19
2019	D1	B1	83.33c	104.09b	187.42b	141.36c	118.04d	259.40c	446.82c
		B2	83.18c	105.02b	188.21b	143.05c	117.43d	260.07c	448.28c
		B3	81.75c	102.77b	184.52b	139.79c	117.06d	256.85c	441.36c
		平均值Average	82.75	103.96	186.72	141.40	117.04	258.44	445.16
	D2	B1	93.80b	117.69a	211.50a	164.48b	127.13c	291.61b	503.11b
		B2	95.64ab	120.44a	216.08a	172.78a	137.22a	309.99a	526.07a
		B3	97.06a	119.06a	216.12a	166.70b	131.63b	298.33b	514.45ab
		平均值Average	95.50	119.06	214.57	167.99	131.99	299.98	514.54
	变异来源 Sources of variation	年份 Year (Y)	**	**	**	**	**	**	**
		密度 Density (D)	**	**	**	**	**	**	**
		行距 Race space (R)	NS	**	NS	**	**	**	**
		年份×密度Y×D	NS	**	**	NS	NS	NS	NS
		年份×行距Y×R	NS	NS	NS	NS	NS	NS	NS
		密度×行距D×R	NS	NS	NS	NS	**	**	NS
		年份×密度×行距 Y×D×R	*	NS	NS	NS	NS	NS	NS

VE: Seeding time; V12: Trumpeting stage; R1: Silking stage; R3: Milking stage; R6: Maturity stage. The same as below
VE：播种期,V12：大喇叭口期,R1：吐丝期,R3：乳熟期,R6：成熟期。下同

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2.5 扩行缩株对夏玉米植株形态特征的影响

密度和行距对茎秆面积、茎叶夹角和叶向值影响显著（表4）。D2较D1茎秆面积显著降低,说明D2较D1抗倒伏能力降低。玉米群体结构2个主要参数茎叶夹角跟叶向值影响群体透光和受光姿态。茎叶夹角表现为D2<D1,叶向值趋势相反,说明植株通过一定自动调节能力,株型变紧凑,在一定程度上减缓了群体密度增加造成个体受光变差的问题。

Table 4
表4
表4扩行缩株对夏玉米植株形态特征的影响
Table 4Effects of line-spacing expansion and row-spacing shrinkage on plant morphological characteristics of summer maize

年份 Year	密度 Density	行距 Row space	株高 Plant height (cm)	穗位高 Ear height (cm)	穗位系数 Ear ratio (%)	茎秆横截面积 Stalk area (cm²)	茎叶夹角 Leaf angle (°)	叶向值 LOV
2018	D1	B1	247.00a	122.50a	49.60a	4.36a	24.33bc	61.79bc
		B2	248.75a	121.25a	48.74a	4.45a	25.64b	59.50c
		B3	251.25a	122.50a	48.76a	4.31a	27.64a	56.22d
		平均值Average	249.00	122.08	49.03	4.37	25.87	59.17
	D2	B1	252.67a	127.50a	50.46a	3.32c	21.23d	66.36a
		B2	252.25a	124.23a	49.25a	3.59b	23.91c	62.94b
		B3	254.17a	124.62a	49.03a	3.46bc	25.50b	60.32bc
		平均值Average	253.03	125.78	49.71	3.46	23.55	63.21
2019	D1	B1	253.89a	118.50c	46.67a	4.79a	24.35bc	60.91b
		B2	256.75a	121.20bc	47.21a	4.64a	25.66b	56.93c
		B3	252.60a	116.80c	46.24a	4.75a	27.65a	55.25c
		平均值Average	254.41	118.83	46.71	4.73	25.89	57.70
	D2	B1	257.75a	128.13a	49.71a	3.66c	21.22d	64.96a
		B2	259.29a	125.83ab	48.53a	3.99b	23.93c	62.30ab
		B3	265.10a	127.90a	48.25a	4.05b	25.51b	60.35b
		平均值Average	260.71	127.29	48.82	3.90	23.55	62.54
	变异来源 Sources of variation	年份 Year (Y)	*	NS	**	**	NS	NS
		密度 Density (D)	NS	**	NS	**	**	**
		行距 Race space (R)	NS	NS	NS	*	**	**
		年份×密度Y×D	NS	NS	NS	NS	NS	NS
		年份×行距Y×R	NS	NS	NS	NS	NS	NS
		密度×行距D×R	NS	NS	NS	**	NS	NS
		年份×密度×行距 Y×D×R	NS	NS	NS	NS	NS	NS

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在D1密度下,不同处理对茎秆面积影响不显著,茎叶夹角总体表现为B3>B2>B1,叶向值趋势相反（除2019年B2和B3处理无显著差异）。在D2密度下,B2和B3处理茎秆面积均显著高于B1处理,在一定程度提高了D2密度下群体抗倒伏性,而B2和B3处理间差异不显著;茎叶夹角和叶向值变化与D1密度各处理表现一致,表明扩行缩株使叶片行间的生长空间相对加大,叶片的形态变得较为舒展。

2.6 扩行缩株对夏玉米透光率及消光系数的影响

密度和扩行缩株模式及二者互作效应对夏玉米透光率及消光系数有极显著影响（表5）。玉米群体内的透光率随测定高度的增加而增大,随生育时期的推进而增加。D2较D1群体内透光率降低,底层透光率降低幅度最大。可见增密以后穗位以上冠层光能截获量明显增加,造成中下层光照降低。在吐丝期D2穗位层和底层2年平均透光率较D1分别减少26.26%和63.37%;在乳熟期2年平均透光率较D1分别减少22.74%和57.35%。

Table 5
表5
表5扩行缩株对夏玉米透光率及消光系数的影响
Table 5Effects of line-spacing expansion and row-spacing shrinkage on light transmittance and extinction coefficient of summer maize

年份 Year	密度 Density	行距 Row space	透光率 (%)				消光系数 Extinction coefficient equation
			吐丝期 Silking		乳熟期 Milking		消光系数 Extinction coefficient equation
			穗位层Ear layer	底层Bottom	穗位层Ear layer	底层Bottom	吐丝期Silking	乳熟期Milking
2018	D1	B1	25.19d	9.61c	25.94d	11.38c	0.44c	0.43b
		B2	26.34c	14.94b	27.22c	17.19b	0.35e	0.35d
		B3	36.69 a	20.83a	37.09a	22.46a	0.30f	0.31e
		平均值Average	29.41	15.13	30.08	17.34	0.36	0.36
	D2	B1	15.45f	3.19f	16.46f	5.92f	0.54a	0.50a
		B2	19.31e	4.92e	20.22e	6.82e	0.46b	0.45b
		B3	29.32b	8.64d	31.23b	10.76d	0.40d	0.39c
		平均值Average	21.36	5.58	22.64	7.83	0.47	0.45
2019	D1	B1	23.19d	8.35c	24.39d	12.84c	0.46c	0.43c
		B2	25.22c	16.03b	25.93c	18.03b	0.34e	0.36d
		B3	33.93a	18.01a	35.05a	21.37a	0.32f	0.33e
		平均值Average	27.45	14.13	28.46	17.41	0.37	0.37
	D2	B1	14.45f	3.01f	17.23f	5.46f	0.58a	0.55a
		B2	19.49e	4.56e	20.62e	6.22e	0.49b	0.49b
		B3	27.75b	7.83d	29.92b	9.05d	0.42d	0.44c
		平均值Average	20.56	5.13	22.59	6.91	0.50	0.49
	变异来源 Sources of variation	年份 Year (Y)	**	*	**	NS	**	**
		密度 Density (D)	**	**	**	**	**	**
		行距 Race space (R)	**	**	**	**	**	**
		年份×密度Y×D	**	**	**	**	**	**
		年份×行距Y×R	**	**	**	**	**	**
		密度×行距D×R	**	**	**	**	**	**
		年份×密度×行距 Y×D×R	NS	**	NS	NS	NS	NS

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同一密度下,随种植行距增大,群体内透光率均增加,B3处理透光率最大,不同生育期均表现为B3>B2>B1,且差异显著,穗位层透光率增加幅度要小于底层透光率增加幅度,且随生育期推进,增加幅度减小。D1密度下,吐丝期B2和B3处理穗位层及底层透光率较B1处理显著增加,2年均值提高了6.57%、45.97%（穗位层）和72.44%、116.26%（底层）;在乳熟期穗位层及底层平均透光率较B1分别增加5.60%、43.32%（穗位层）和39.65%、73.79%（底层）。D2密度下,吐丝期B2和B3处理穗位层以及底层平均透光率较B1分别增加29.77%、90.87%（穗位层）和52.90%、165.65%（底层）;在乳熟期穗位层以及底层平均透光率较B1分别增加21.22%、81.51%（穗位层）和14.59%、74.03%（底层）。可以看出D2密度下,适宜的扩行缩株模式对群体内光分布的调节更趋向合理,有利于在高密度下构建高光效的群体结构。

消光系数与群体内透光率趋势相反。吐丝期D2密度平均消光系数较D1密度增加30.82%;灌浆期增加了21.58%。同一密度下,扩大行距消光系数均减小,表现为B1>B2>B3。吐丝期LAI达到峰值,对冠层光分布影响最大,对该时期消光系数K进行回归分析发现,种植密度（X₁,株/hm²）和行距（X₂,cm）与K值呈极显著线性相关,回归方程为K=0.148+ 8.00×10^-6 X₁-3.63×10^-3 X₂（R²=0.946**,n=12）,在相同行距下,密度每增加10 000株/hm²,K增加0.0800;在相同密度下,行距每增加10 cm,K值降低0.0363。种植密度和行距配置可以通过建立适宜的消光系数,来改善田间透光条件。

2.7 扩行缩株对夏玉米干物质积累与转运的影响

从表6可知,密度对夏玉米干物质积累和转运的影响达显著水平。吐丝期干物质积累量、成熟期干物质积累量、花后干物质转运量和干物质转移对籽粒的贡献均表现为D2较D1显著增加（除2018年花后干物质积累量B1和B3处理）。在D1密度下,各处理间成熟期干物质积累量和花后干物质积累量均无显著差异。在D2密度下,B2处理成熟期干物质积累量和花后干物质积累量显著高于B1处理（P<0.05）,2018年花后干物质转移量无显著差异,2019年B2处理花后干物质转移量较B1处理显著降低,而花后干物质转运对籽粒的贡献率显著低于B1和B3处理。可见高密度下,B2处理产量的提高主要是通过增加花后干物质积累量来实现的。

Table 6
表6
表6扩行缩株对夏玉米干物质积累与转运的影响
Table 6Effects of line-spacing expansion and row-spacing shrinkage on dry matter accumulation and transport of summer maize

年份 Year	密度 Density	行距 Row space	吐丝期干物质积累量 DMAS (t·hm^-2)	成熟期干物质积累量DMAM (t·hm^-2)	花后干物质积累量DMAAS (t·hm^-2)	花后干物质转运量TADM (t·hm^-2)	花后干物质转运对籽粒的贡献率 CGDMT (%)
2018	D1	B1	10.91b	18.67cd	7.75b	1.75b	18.42c
		B2	10.94b	18.62d	7.68b	1.72b	18.25c
		B3	10.92b	18.58d	7.66b	1.76b	18.64c
		平均值Average	10.92	18.62	7.70	1.74	18.44
	D2	B1	11.39a	19.27bc	7.88b	2.72a	31.32a
		B2	11.72a	19.99a	8.28a	2.65a	29.64b
		B3	11.60a	19.40ab	7.81b	2.69a	31.31a
		平均值Average	11.57	19.56	7.99	2.68	30.76
2019	D1	B1	10.46c	18.07c	7.61c	1.98d	20.64c
		B2	10.58c	18.25c	7.67c	2.03d	20.91c
		B3	10.50c	18.12c	7.62c	1.98d	20.61c
		平均值Average	10.51	18.15	7.63	2.00	20.72
	D2	B1	11.47ab	19.60b	8.13b	2.69a	30.40a
		B2	11.73a	20.25a	8.53a	2.59b	28.50b
		B3	11.22b	19.38b	8.15b	2.42c	28.00b
		平均值Average	11.47	19.74	8.27	2.57	28.97
	变异来源 Sources of variation	年份 Year (Y)	**	NS	NS	**	NS
		密度 Density (D)	**	**	**	**	**
		行距 Race space (R)	NS	*	**	**	**
		年份×密度Y×D	*	*	**	**	**
		年份×行距Y×R	NS	NS	NS	**	**
		密度×行距D×R	NS	NS	**	**	**
		年份×密度×行距 Y×D×R	NS	NS	NS	*	*

DMAS: Dry matter accumulation at silking; DMAM: Dry matter accumulation at maturity; DMAAS: Dry matter accumulation after silking; TADM: Transfer amount of dry matter; CGDMT: Contribution to grain of dry matter transportation
DMAS：吐丝期干物质积累量;DMAM：成熟期干物质积累量;DMAAS：花后干物质积累量;TADM：干物质转运量;CGDMT：干物质转运对籽粒的贡献

新窗口打开|下载CSV

通过对D2密度下不同叶层叶面积指数与花后干物质积累量相关分析发现,吐丝期穗位以上叶与花后干物质积累量呈负相关（r=-0.444）,而穗位层及穗位层以下叶片与花后干物质积累量呈显著正相关（r=0.989*和0.958*）,乳熟期各叶层均与花后干物质积累量呈正相关关系（r=0.554,0.989和0.758）。说明在吐丝期适当减小上部叶面积,而在花后保持较高的叶面积,特别是增大中下层叶面积,对于花后干物质的积累具有重要作用,有利于产量提高。

3 讨论

3.1 扩行缩株与密度对夏玉米产量的影响

除适当肥水管理外,增加种植密度是提高夏玉米产量的关键措施之一^[24]。本试验结果表明,D2较D1密度,群体LAI和总光合势显著增加,群体透光率降低,光能截获增加,促进光合产物的积累与转运,最终使玉米群体产量显著增加,可以看出增密是玉米群体产量提高的有效途径。前人研究表明,黄淮海地区种植密度90 000株/hm²可以充分发挥生长潜能,获得高产^[16,25],本研究考虑黄淮海地区阴雨寡照,设置最高密度为82 500株/hm²,并且在试验期间均未发生倒伏,认为该密度是适合黄淮海地区的种植密度。在高密度条件下,合理的行株距配置是发挥玉米个体发育潜力,协调玉米群体与个体的发展,保证玉米群体产量提高的关键^[16]。金容等^[26]研究表明,高密度下宽窄行有利于促进玉米雌雄穗分化发育,增加玉米穗行数、行粒数、穗长,减小秃尖长度。本试验条件下,D2密度下B2处理产量、行粒数和穗粒数均显著高于其他各处理,表明在高密度条件下适当扩行缩株主要是增加玉米行粒数,进而提高穗粒数来实现产量提高,这与刘永忠等^[19]关于春玉米在高密度下适当缩小行距有利于产量提高的结果不一致。这可能与玉米生长季光辐射存在差异有关,因此玉米的株行距配置要因当地光照和密度等生态条件而异。此外,穗行数和行粒数形成时期不同,在生育前期决定穗行数,植株较小对资源需求少,个体间竞争较弱;而在开花期前后决定行粒数,此时植株较大,在增密后个体间竞争强烈,会导致籽粒的败育^[22]。表明B2处理能够更好地协调夏玉米整个生育期内个体与群体间的生长发育,群体结构更加合理,是增密条件下进一步发挥产量潜力的有效措施。

3.2 扩行缩株与密度对群体冠层结构的影响

种植密度决定群体的大小,而行株距配置则决定群体的均匀性^[8,27]。通过行株距配置调节冠层形态结构和资源利用^[18],从而强化群体的密度效应,有利于群体产量提高^[16,28]。叶面积在冠层中的分布影响光能利用,是反映冠层结构性能的重要指标^[23,29]。卫丽等^[7]研究表明增密后植株下部叶片在灌浆后期因衰老的加剧,光合性能低于中、上部叶片,通过宽窄行种植使下部叶片受光情况明显改善,其功能期也得到延长,光合能力显著提高,对产量的贡献加大。本研究表明,D2密度下B2处理的LAI从吐丝到乳熟期显著高于其他各处理,并且LAI的提高主要通过增加中下部叶片的叶面积。从吐丝期到乳熟期,棒三叶以下叶片较B1处理增幅从3.70%增加到12.43%,在吐丝期后叶片衰老延缓,有利于扩大并维持较大的光合源,解决高密度下群体源不足限制增产的问题^[11],促进群体产量潜力的发挥。通过行株距配置来改善株型^[28]和叶角^[18,26]等冠层结构特征,能增加光的有效截获,增强群体光合能力,提高玉米在高密度下的耐密性,有利于获得高产^[30,31]。本研究中随着行距增大,茎叶夹角增大,叶向值减小,扩行缩株使叶片生长空间相对加大,变得较为舒展,提高了冠层的光能截获,减少了因扩大行距可能带来的光能损失。此外,D2密度下B2处理较B1处理茎秆横截面积增加,在一定程度提高了高密度下群体抗倒伏性。较高的叶面积指数,吐丝后较长的绿叶持续期,棒三叶及其以下叶在LAI增加和穗位茎叶夹角大小的调节方面的贡献,使高密度下B2处理群体形成了高光效的冠层结构,在吐丝期至成熟期有较高的光合势,促进花后干物质的积累,有利于产量的提高。

3.3 扩行缩株与密度对群体冠层光分布与干物质积累的影响

叶片的光合生产能力对作物产量至关重要,而光合作用大小主要与冠层内光分布是否合理有关^[12]。玉米生长与太阳辐射的匹配对获得高产具有重要意义^[10]。通过行距配置能够提高群体光分布的均匀性,对于构建高光效的群体结构,促进产量的提高具有重要作用^[16,26]。杨吉顺等^[16]和梁熠等^[17]认为适宜宽窄行有利于扩大光合面积,增加中部冠层的透光率,充分利用不同层次的光资源。本研究表明,D2较D1密度透光率显著减小,而随着行距扩大,群体内透光率显著增加,穗位层透光率增加幅度要小于底层透光率增加幅度,且随生育期推进增加幅度减小。在D1密度下,群体的透光率明显过大,漏光损失严重,不利于产量的提高。在D2密度下,适当扩行缩株对于改善群体光分布的效果更显著,B3处理群体透光率显著大于其他处理,消光系数较低,存在较多的漏光损失;B1处理植株间光能和养分资源竞争加剧,消光系数较高,群体内光衰减严重,透光条件差,均不利于产量的提高,而B2处理穗位层透光率在19.31%—20.62%,这与刘广周^[32]在产量潜力22.5 t·hm^-2水平的高产群体冠层结构下测定穗位透光率结果（19%）比较接近。此外,B2处理在吐丝期LAI最大时,底层透光率2年均值在4.74%,存在一定的漏光,但截光率在95%以上,达到玉米高产群体要求^[33]。D2密度下B2处理较B1处理穗位层透光率显著提高,便于增加中间层叶片的光能截获,并延缓冠层叶片衰老^[34],同时增强了冠层底部的光辐射量,优化密植后群体的冠层光分布,满足了叶片光合作用对光能的需要,延缓了中下部叶片衰老（表2）,维持了密植条件下花后功能叶的高值持续期,促进干物质的积累,从而显著提高产量。前人研究表明,群体冠层的光截获与干物质积累和产量密切相关^[35]。光辐射减弱和增加种植密度后,冠层内的太阳辐射急剧下降,植株间对有限的太阳辐射资源的竞争加剧,叶片的光合能力下降,特别是冠层的下部叶片,使干物质积累量减少^[10]。研究表明干物质的积累随群体结构的差异而变化^[36],高密度下宽窄行种植可以有效调节植株个体与群体间的矛盾,提高干物质积累量^[16]。本研究表明,在D2密度下,B2处理花后干物质积累量显著高于其他处理,并且花后干物质转移量适宜,有利于营养器官生理功能维持和产量提高。B2处理在生育中后期维持较高的群体光合势,且冠层内光分布更均匀,减弱了群体内对光资源的竞争,减缓营养器官的物质转移,有利于延长群体叶片功能期,提高花后光合同化物的生产,促进干物质的积累,从而实现高产。

4 结论

本试验条件下,种植密度在82 500株/hm²时,采用扩行缩株种植模式,行距调整到80 cm时产量最高,增产的主要原因是扩行缩株模式显著增加透光率,叶面积指数增加且叶片功能期持续时间长,改善了冠层结构和冠层光合性能,而且协调了植株个体与群体的发展,显著提高了花后干物质积累量,实现群体结构优化,促进玉米群体产量的提高。因此,在增密条件下,采用扩行缩株模式（80 cm等行距）能更好与黄淮海地区光资源匹配,是进一步提高产量的有效栽培方式。

参考文献原文顺序
文献年度倒序
文中引用次数倒序
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中国农业科学, 2017, 50(11): 1960-1972.

DOI:10.3864/j.issn.0578-1752.2017.11.002 URL [本文引用: 2]

【Objective】Enhancing the maize plant population has undergone a constant evolution over the years, with the purpose of increasing the crop yield. However, the rational density range was determined by environmental condition, varieties and management. The objective of this work was to reveal the approach of enhancing maize yield in the future by analyzing the change trend of planting density and its influencing factors in major producing regions. 【Method】 The research data have been obtained over the Project of Sending Agricultural Technology into Farmers’ Homes and National Maize Industrial Technology System from 2005 to 2016, including 23 provinces, more than 267 counties. From this investigation, 117 960 farmer production investigation data samples were obtained from the Northern China spring maize planting region (NM), the Northwest China maize planting region (NWM), the Huang-Huai-Hai Plain summer maize planting region (HPM), the Southwest China maize planting region(SM) and the Southern China sweet-waxy maize planting region (SWM). The number of harvested plants surveyed in nationwide investigation was used to analyze the planting density of maize main producing region and different ecological regions. The sample data were verified and complemented by averaging the values of 5 neighboring points. According to the regional environmental condition and planting patterns, the main maize producing regions have divided into 25 typical ecological regions. Boxplot analysis and Tukey’s honestly significant difference (HSD) test method were used to compare the planting density difference and its significance in different regions. Evolutionary trends of county-scale planting density in different ecological regions were subjected to the fitting linear model to analyze inter-annual trend of planting density and its significance.【Result】The results showed that there were significant differences of planting densities in different regions. At present (2014-2016), the planting density of the main producing region respectively were 6.77×10⁴, 6.19×10⁴, 5.91×10⁴, 5.13×10⁴ and 4.80×10⁴ plants/hm² in NWM, HPM, NM, SWM and SM. The planting density in NWM was significantly higher (P<0.01) than other regions. Furthermore, planting density in SWM and SM was significantly lower (P<0.01) than that in NWM, HPM and NM. From 2005 to 2016, the inter-annual variability of planting density showed a significant increase in NM. In NWM and SM, the planting density kept it steady between 2009 and 2016. The planting density in HPM increased obviously from 2005 to 2009 and remained stable after 2009. Planting density in SWM showed a significant decreasing trend.【Conclusion】Dense planting cultivation is commonly acknowledged by both the government and the academic researchers. However, the planting density evolution in the main production regions and different ecological regions is not uniform. Regional environmental condition is the key factor for determining the planting density, and reasonable cultivation techniques and appropriate density-resistant varieties are effective approaches to overcome environmental constraints and increase planting density. Consequently, further analysis of the promotion and restriction increase planting density factors, including environmental condition, varieties and management, will provide a theoretical foundation for establishing regional dense planting management mode.

MING

, XIE

R Z

, HOU

, LI

L L

, WANG

K R

, LI

S K

. Changes of maize planting density in China
Scientia Agricultura Sinica, 2017, 50(11): 1960-1972. (in Chinese)

DOI:10.3864/j.issn.0578-1752.2017.11.002 URL [本文引用: 2]

吕丽华, 陶洪斌, 夏来坤, 张雅杰, 赵明, 赵久然, 王璞. 不同种植密度下的夏玉米冠层结构及光合特性
作物学报, 2008, 34(3): 447-455.

DOI:10.3724/SP.J.1006.2008.00447 URL [本文引用: 2]

研究了种植密度对夏播玉米(CF008、郑单958和金海5号）冠层结构及光合特性的影响，目的是通过密度调控，构建高效冠层，发挥品种潜力，同时确立不同夏玉米品种高产高效冠层的定量化技术指标。结果表明，3个夏玉米品种均在中或低密度下（CF008为9.75和11.25万株 hm-2，郑单958为8.25和9.75万株 hm^-2，金海5号为6.75和8.25万株 hm^-2）构建的冠层较合理，冠层光合性能较高。冠层内透光率、叶夹角、茎粗、叶绿素相对含量（SPAD值）和净光合速率（Pn）均随着密度的增加而降低，说明高密度易造成群体内光分布不合理，导致光合性能的降低。灌浆中期前群体光合势（LAD）和叶面积指数（LAI）均表现为中或高密度条件下较高，而后为中或低密度下较高，并且吐丝后LAD所占比率为中或低密度处理显著高于高密度处理，说明高密度条件下冠层结构不合理，造成生育后期叶片提早衰老。在中或低密度下，群体穗位层透光率较大，吐丝期和灌浆中期分别为13.4%~19.45%和16.19%~21.48%；叶面积发展动态较为合理，吐丝期LAI达5.59~6.75，成熟期仍然保持在2.24~3.68，尤其中上层叶片LAI高值持续期较长；吐丝期中上层叶片Pn达到33.6~43.8 μmol CO2 m^-2 s^-1；吐丝后的群体LAD较高，特别是中密度下LAD达172.01~235.91 m2 d m-2，后期光合面积持续时间较长，更有利于玉米产量的提高。

Lü

L H

, TAO

H B

, XIA

L K

, ZHANG

Y J

, ZHAO

J R

, WANG

. Canopy structure and photosynthesis traits of summer maize under different planting densities
Acta Agronomical Sinica, 2008, 34(3): 447-455. (in Chinese)

DOI:10.3724/SP.J.1006.2008.00447 URL [本文引用: 2]

SONG

Q F

, ZHANG

G L

, ZHU

X G

. Optimal crop canopy architecture to maximise canopy photosynthetic CO₂ uptake under elevated CO₂-A theoretical study using a mechanistic model of canopy photosynthesis
Functional Plant Biology, 2013, 40(2): 109-124.

DOI:10.1071/FP12056 URL [本文引用: 1]

Canopy architecture has been a major target in crop breeding for improved yields. Whether crop architectures in current elite crop cultivars can be modified for increased canopy CO2 uptake rate (A(c)) under elevated atmospheric CO2 concentrations (C-a) is currently unknown. To study this question, we developed a new model of canopy photosynthesis, which includes three components: (i) a canopy architectural model; (ii) a forward ray tracing algorithm; and (iii) a steady-state biochemical model of C-3 photosynthesis. With this model, we demonstrated that the A(c) estimated from 'average' canopy light conditions is similar to 25% higher than that from light conditions at individual points in the canopy. We also evaluated theoretically the influence of canopy architectural on A(c) under current and future C-a in rice. Simulation results suggest that to gain an optimal A(c) for the examined rice cultivar, the stem height, leaf width and leaf angles can be manipulated to enhance canopy photosynthesis. This model provides a framework for designing ideal crop architectures to gain optimal A(c) under future changing climate conditions. A close linkage between canopy photosynthesis modelling and canopy photosynthesis measurements is required to fully realise the potential of such modelling approaches in guiding crop improvements.

[14]

HUANG

S B

, GAO

Y B

, LI

Y B

, XU

L N

, TAO

H B

, WANG

. Influence of plant architecture on maize physiology and yield in the Heilonggang River valley
Crop Journal , 2017, 5(1): 52-62.

DOI:10.1016/j.cj.2016.06.018 URL [本文引用: 1]

[15]

WEI

S S

, WANG

X Y

, JIANG

, DONG

S T

. Physiological and proteome studies of maize ( Zea mays L.) in response to leaf removal under high plant density
BMC Plant Biology, 2018, 18: 378.

URLPMID:30594144 [本文引用: 1]

[16]

杨吉顺, 高辉远, 刘鹏, 李耕, 董树亭, 张吉旺, 王敬锋. 种植密度和行距配置对超高产夏玉米群体光合特性的影响
作物学报, 2010, 36(7), 1226-1233.

DOI:10.3724/SP.J.1006.2010.01226 URL [本文引用: 9]

With different plant population densities (6.75´10⁴, 9.00´10⁴, and 11.25´10⁴ plants ha^-1), the effects of the deneity and row spacing on grain yield and canopy apparent photosynthesis were studied in this article. The results were as follows: with the increase of planting density, grain yield, leaf area index (LAI) and capture efficiency of photosynthestically active radiation(PAR) in upper leaf layer, as well as canopy apparent photosynthesis (CAP) and canopy respiration (CR) and dry matter quantity increased accordantly; but, chlorophyll content and capture efficiency of PAR in the middle and lower layers of canopy decreased. Within different row spacing treatments, the wide-narrow row spacing were not superior to the uniform one significantly at 6.75´10⁴ plants ha^-1. However, at 9.00´10⁴ and 11.25´10⁴ plants ha^-1, grain yield, LAI, chlorophyll content, capture efficiency of PAR in middle leaf layer and average rate of CAP after anthesis in row spacing of “80 cm+40 cm” were remarkably higher than those in other three row spacings (uniform, 70 cm + 50 cm, 90 cm + 30 cm); while CR/TCAP (ratio of canopy respiration to total canopy apparent photosynthesis) in row spacing of ’80 cm+40 cm’ was the lowest, compared to the others. From the above, it was suggested that at higher plant density the row spacing of ’80 cm+40 cm’ could enlarge photosynthetic area, enhance PAR in middle leaf layer, increase CAP, reduce CR and improve grain yield.

YANG

J S

, GAO

H Y

, LIU

, LI

, DONG

S T

, ZHANG

J W

, WANG

J F

. Effects of planting density and row spacing on canopy apparent photosynthesis of high-yield summer corn
Acta Agronomica Sinica, 2010, 36(7): 1226-1233. (in Chinese)

DOI:10.3724/SP.J.1006.2010.01226 URL [本文引用: 9]

梁熠, 齐华, 王敬亚, 白向历, 王晓波, 刘明, 孟显华, 许晶. 宽窄行栽培对玉米生长发育及产量的影响
玉米科学, 2009, 17(4): 97-100.

[本文引用: 3]

LIANG

, QI

, WANG

J Y

, BAI

X L

, WANG

X B

, LIU

, MENG

X H

, XU

. Effects of growth and yield of maize under wide and narrow row cultivation
Journal of Maize Sciences, 2009, 17(4): 97-100. (in Chinese)

[本文引用: 3]

[18]

苌建峰, 张海红, 李鸿萍, 董朋飞, 李潮海. 不同行距配置方式对夏玉米冠层结构和群体抗性的影响
作物学报, 2016, 42(1): 104-112.

DOI:10.3724/SP.J.1006.2016.00104 URL [本文引用: 4]

为探究行距配置方式对冠层微气象因子及群体抗逆性的影响，明确夏玉米适宜的行距配置方式，在方城和辉县设置大田试验，以3个不同株高类型的玉米杂交种为材料(中秆品种郑单958、高秆品种先玉335和矮秆品种512-4)，设置2个种植密度(60 000株 hm^-2和75 000株 hm^-2)，研究了5种行距配置方式(50 cm、60 cm、70 cm、80 cm等行距和80 cm+40 cm宽窄行)下冠层结构和群体抗逆性的变化。结果表明，不同株高类型杂交种在相同密度下，随行距扩大，株型变得松散，穗部叶片叶向值减小，并偏离种植行，向种植行垂直方向发展，冠层温湿度降低，群体抗逆性增强，但冠层光照截获率降低，产量也随之减少。对比发现，不同品种和密度下，60 cm等行距能够较好地协调冠层微气象因子与玉米产量的关系，叶片分布适宜，冠层温湿度和光能分布合理，显著提高了中下部的光能截获率，病虫害和倒伏的发生率较低，获得最高产量的频率最高，且适宜机械化田间作业，建议作为适宜黄淮海地区推广的种植方式。

CHANG

J F

, ZHANG

H H

, LI

H P

, DONG

P F

, LI

C H

. Effects of different row spaces on canopy structure and resistance of summer maize
Acta Agronomical Sinica, 2016, 42(1): 104-112. (in Chinese)

DOI:10.3724/SP.J.1006.2016.00104 URL [本文引用: 4]

刘永忠, 李万星, 曹晋军, 靳鲲鹏. 高密度条件下行距配置对春玉米光合特性及产量的影响
华北农学报, 2017, 32(3): 111-117.

[本文引用: 3]

LIU

Y Z

, LI

W X

, CAO

J J

, JIN

K P

. Effects of row spacing on photosynthetic characteristics and yield of spring maize under high density
Acta Agriculturae Boreali-Sinica, 2017, 32(3): 111-117. (in Chinese)

[本文引用: 3]

[20]

徐田军, 吕天放, 赵久然, 王荣焕, 陈传永, 刘月娥, 刘秀芝, 王元东, 刘春阁. 玉米生产上3个主推品种光合特性、干物质积累转运及灌浆特性
作物学报, 2018, 44(3): 414-422.

DOI:10.3724/SP.J.1006.2018.00414 URL [本文引用: 1]

T J

, Lü

T F

, ZHAO

J R

, WANG

R H

, CHEN

C Y

, LIU

Y E

, LIU

X Z

, WANG

Y D

, LIU

C G

. Photosynthetic characteristics, dry matter accumulation and translocation, grain filling parameter of three main maize varieties in production
Acta Agronomica Sinica, 2018, 44(3): 414-422. (in Chinese)

DOI:10.3724/SP.J.1006.2018.00414 URL [本文引用: 1]

[21]

任佰朝, 张吉旺, 董树亭, 赵斌, 刘鹏. 生育前期淹水对夏玉米冠层结构和光合特性的影响
中国农业科学, 2017, 50(11): 2093-2103.

DOI:10.3864/j.issn.0578-1752.2017.11.015 URL [本文引用: 1]

【Objective】 The objective of this study is to investigate the effects of waterlogging on canopy structure and photosynthetic characteristics of summer maize under field conditions. 【Method】 Two summer maize cultivars Denghai605 (DH605) and Zhengdan958 (ZD958) were used as experimental materials. Experimental treatments consisted of waterlogging at the third leaf stage for 3 d (V3-3) and for 6 d (V3-6), waterlogging at the sixth leaf stage for 3 d (V6-3) and for 6 d (V6-6), and no waterlogging (CK). The field experiment was performed to explore the effects of waterlogging for different durations (3 and 6 days) on photosynthetic intensity, net photosynthetic rate, canopy light transmittance and its hemispheric gray images, and grain yield of summer maize at the third leaf stage (V3) and sixth leaf stage (V6). 【Result】 Results showed that leaf area index was significantly reduced after waterlogging. Waterlogging significantly increased group light transmittance, and led to a remarkable reduction of light interception rate. Group light transmittance of summer maize was more susceptible to waterlogging damage at V3, followed by V6, and damage was increased with the increasing waterlogging duration. The light transmittances of ear layer were increased by 96.0% and 70.2% for V3-6 in DH605 and ZD958, respectively, compared to CK. That ground floor increased by 68.9% and 71.9% for V3-6 in DH605 and ZD958, respectively, compared to CK. Waterlogging significantly decreased group photosynthetic potential (LAD) and net photosynthetic rate (Pn)；The most decrease of Pn of two hybrids was found at V3-6, with 23.5% and 20.3% in DH605 and ZD958, respectively. LAD of V3-6 for DH605 was decreased by 68.5%, 45.0%, 31.6%, 25.0%, and 37.5% at seedling-V6, V6-the twelfth leaf stage (V12), V12-the flowering stage (VT), VT-the milking stage (R3), and R3-the physiological maturity stage (R6), respectively. ZD958 decreased by 62.4%, 37.1%, 25.8%, 21.7%, and 38.5%, respectively. The reduction of LAD and Pn led to the decrease of photoassimilates. Dry matter weight of V3-3, V3-6, V6-3, and V6-6 for DH605 was decreased by 12.4%, 24.8%, 9.3%, and 21.1%, ZD958 decreased by 17.3%, 26.7%, 12.5%, and 23.9%, respectively. In addition, waterlogging decreased harvest index, with the most significant reduction in V3-6 with a decrease of 13.3% and 13.8% for DH605 and ZD958. The degradation of canopy structure and photosynthetic characteristics resulted in a significant reduction of maize yield after waterlogging. Grain yield of V3-3, V3-6, V6-3, and V6-6 for DH605 was decreased by 23.2%, 35.9%, 17.0%, and 22.7%, ZD958 decreased by 20.0%, 35.7%, 15.0%, and 27.1%, respectively. 【Conclusion】 Waterlogging significantly decreased leaf area index and ground photosynthetic potential, led to the reduction of light interception rate and photosynthetic performance, decreasing net photosynthetic rate, eventually resulted in a remarkable reduction of summer maize yield. Canopy structure and photosynthetic characteristics of summer maize was more susceptible to waterlogging damage at V3, followed by V6, damage was increased with the increasing waterlogging duration.

REN

B Z

, ZHANG

J W

, DONG

S T

, ZHAO

, LIU

. Effect of waterlogging at early period on canopy structure and photosynthetic characteristics of summer maize
Scientia Agricultura Sinica, 2017, 50(11): 2093-2103. (in Chinese)

DOI:10.3864/j.issn.0578-1752.2017.11.015 URL [本文引用: 1]

TESTA

, REYNERI

, BLANDINO

. Maize grain yield enhancement through high plant density cultivation with different inter-row and intra-row spacings
European Journal of Agronomy, 2016, 72: 28-37.

DOI:10.1016/j.eja.2015.09.006 URL [本文引用: 2]

[23]

张玉芹, 杨恒山, 高聚林, 张瑞富, 王志刚, 徐寿军, 范秀艳, 杨升辉. 超高产春玉米冠层结构及其生理特性
中国农业科学, 2011, 44(21): 4367-4376.

DOI:10.3864/j.issn.0578-1752.2011.21.005 URL [本文引用: 2]

【Objective】 Canopy structure and canopy functional characteristics of super-high yield spring maize populations were studied to reveal the physiological mechanism of formation of super-high yield, which provided a theoretical basis for cultivation of super-high yield spring maize.【Method】The Jinshan 27 was grown under super-high-yield cultivation (SHY) and normal high-yield cultivation (CK) condition in 2009 and 2010 to assess the indexes of canopy structure and physiological characteristics of super-high yield maize.【Result】Compared with normal high-yield cultivation, the super-high yield spring maize had higher leaf area index (LAI), and three-ear leaves was more obvious after silking stage. Leaf angle of different leaf locations was lower and the leaf direction value was higher than normal high-yield cultivation, and particularly in the three-ear. With the process of the growing period, the difference of photosynthetic potential between the super-high-yield cultivation and the normal high-yield cultivation increased. In the silking stage and milking stage, the difference of the net photosynthetic rate of two cultivation modes was not significant, but canopy photosynthetic ability of super-high cultivation was significantly higher than normal high-yield cultivation. From the silking stage to 40 days, SOD and POD activities were higher than the normal cultivation and MDA content lower than the normal cultivation.【Conclusion】The super-high yield spring maize has higher LAI and population photosynthetic potential, smaller leaf angle and higher leaf direction value, and canopy structure is reasonable. The super-high yield spring maize has stronger SOD and POD activities, lower the MDA content, higher net photosynthetic rate and stronger photosynthetic potential. So under the reasonable cultivation technique condition, collaborative gain can be obtained from super-high-yield spring maize community structure and individual function.

ZHANG

Y Q

, YANG

H S

, GAO

J L

, ZHANG

R F

, WANG

Z G

, XU

S J

, FAN

X Y

, YANG

S H

. Study on canopy structure and physiological characteristics of super-high yield spring maize
Scientia Agricultura Sinica, 2011, 44(21): 4367-4376. (in Chinese)

DOI:10.3864/j.issn.0578-1752.2011.21.005 URL [本文引用: 2]

王洪章, 刘鹏, 董树亭, 张吉旺, 赵斌, 任佰朝. 夏玉米产量与光温生产效率差异分析——以山东省为例
中国农业科学, 2019, 52(8): 1355-1367.

DOI:10.3864/j.issn.0578-1752.2019.08.006 URL [本文引用: 1]

【Objective】 In the present study, the biomass production and resource availability among yield levels were studied to quantify the gap of yield, radiation production efficiency and temperature production efficiency of summer maize in Shandong province. This study aimed to clarify the contribution rate of agricultural production conditions and cultivation measures to yield gap and efficiency gap, and to explore the possibility of synergistic narrow the yield gap and efficiency gap, so as to provide a theoretical basis for closing yield gap and improving resource utilization efficiency. 【Method】 The experiment was conducted in Taian, Zibo and Yantai in Shandong province from 2017 to 2018. Based on the investigation of summer maize production in Shandong province, four management models were designed in consideration of appropriate increase of plant density, optimization of fertilizer and water, increase of yield and efficiency with the same integrated management. The four yield levels, including super high yield (SH), high yield and high efficiency (HH), farmer level (FP) and basic production level (CK), were simulated. And the gap of yield, radiation production efficiency and temperature production efficiency of different yield levels were analyzed. With the integrative analysis of radiation-temperature production potential and crop yield performance, the factors affecting gap of yield and efficiency and the way closing yield gap and increasing efficiency were explored in the present study. 【Result】 At present, the yield gap between radiation temperature potential level and super high yield level, super high yield level and high yield high efficiency level, high yield and high efficiency level and farmer production level, farmer production level and basic production level of summer maize in Shandong province were 5.85, 0.82, 1.90 and 1.35 t·hm ^-2, respectively; The radiation production efficiency gap were 1.74, 0.15, 0.28 and 0.45 g·MJ ^-1, respectively; and the temperature production efficiency gap were 1.09, 0.10, 0.17 and 0.28 kg·hm ^-2·℃ ^-1, respectively. The current uncontrollable factors contributed 58.49% to yield gap, and contributed 66.09% to light and temperature production efficiency. And geographical difference factors contributed 1.98% to yield gap, contributed 2.49% to radiation production efficiency, and contributed 3.24% to temperature production efficiency. There was a significant correlation between the yield gap and the production efficiency gap. SH and HH had higher biomass, mean leaf area index (MLAI) and canopy light energy interception rate than FP and CK. 【Conclusion】 At present, the gap of yield, the radiation production efficiency, and the temperature production efficiency between the farmer production level and the radiation temperature potential level of summer maize in Shandong province were 8.56 t·hm ^-2, 2.17 g·MJ ^-1, and 1.35 kg·hm ^-2·℃ ^-1, respectively, so there was room for improvement in yield and utilization efficiency of radiation and temperature resources. There was a significant correlation between the yield gap and the production efficiency gap, on the basis of existing farmer management measures, the application of high-yield and high-efficiency management mode (increase the plant density of 15 000 plant·hm ^-2, and increasing the amount of fertilization appropriately, changing the one-time fertilization into the sub-fertilization mode with water and fertilizer integration during the stage of sowing, spike formation, flowering, and milking) could narrow the yield gap by 1.90 t·hm ^-2and increase the production efficiency of radiation and temperature resources by 14.74% and 14.41%, respectively, which was an effective technical way to synergistic close yield gap and increase efficiency.

WANG

H Z

, LIU

, DONG

S T

, ZHANG

J W

, ZHAO

, REN

B Z

. Analysis of gap between yield and radiation production efficiency and temperature production efficiency in summer maize-Taking Shandong province as an example
Scientia Agricultura Sinica, 2019, 52(8): 1355-1367. (in Chinese)

DOI:10.3864/j.issn.0578-1752.2019.08.006 URL [本文引用: 1]

刘伟, 张吉旺, 吕鹏, 杨今胜, 刘鹏, 董树亭, 李登海, 孙庆泉. 种植密度对高产夏玉米登海661产量及干物质积累与分配的影响
作物学报, 2011, 37(7): 1301-1307.

DOI:10.3724/SP.J.1006.2011.01301 URL [本文引用: 1]

The effects of plant density on the dry matter accumulation and distribution were studied under high yield condition hoping to provide a scientific basis for the cultivation and breeding of high-yielding maize, using summer maize cultivar Denghai 661 and Nongda 108 were used as the experimental material and planted with different planting densities. The results showed that, population grain yield and dry matter accumulation increased significantly with the increasing of plant density, while the per plant were decreased.Denghai 661 had a high growth potential at 90 000 plant ha^-1, whichwas the optimum plant population for the maximal grain yield. At anthesis and milking stages, the decreaserateof stem dry matter accumulation was greater than that of leafwith increasing plant density,which was on the contrary at maturity stage. So the effects of plant density on stem dry matter accumulation were significantly stronger than that before milking stage, which was on the contrary after milking stage. After milking stage,the transportation efficiency of both stem and leaf reduced significantly with the increasing of plant density, the contribution rate of stem also reduced significantly, leaf increased. The stem dry mattertransportation contributed more than leaf’s to the grain yield under the density from 30 000 to 90 000 plant ha^-1, butthe leaf dry matter transportationcontributed more than stems to the grain yield under the density from 105 000 to 135 000 plant ha^-1.

LIU

, ZHANG

J W

, Lü

, YANG

J S

, LIU

, DONG

S T

, LI

D H

, SUN

Q Q

. Effect of plant density on grain yield dry matter accumulation and partitioning in summer maize cultivar Denghai 661
Acta Agronomica Sinica, 2011, 37(7): 1301-1307. (in Chinese)

DOI:10.3724/SP.J.1006.2011.01301 URL [本文引用: 1]

金容, 李钟, 杨云, 周芳, 杜伦静, 李小龙, 孔凡磊, 袁继超. 密度和株行距配置对川中丘区夏玉米群体光分布及雌雄穗分化的影响
作物学报, 2020, 46(4): 614-630.

[本文引用: 3]

JIN

, LI

, YANG

, ZHOU

, DU

L J

, LI

X L

, KONG

F L

, YUAN

J C

. Effects of density and row spacing on population light distribution and male and female spike differentiation of summer maize in hilly area of central Sichuan
Acta Agronomica Sinica, 2020, 46(4): 614-630. (in Chinese)

[本文引用: 3]

[27]

MOHAMMADI

G R

, GHOBADI

M E

, SHEIKHEHPOOR

. Phosphate biofertilizer, row spacing and plant density effects on corn yield and weed growth
American Journal of Plant Sciences, 2012, 3: 425-429.

DOI:10.4236/ajps.2012.34051 URL [本文引用: 1]

[28]

魏珊珊, 王祥宇, 董树亭. 株行距配置对高产夏玉米冠层结构及籽粒灌浆特性的影响
应用生态学报, 2014, 25(2): 441-450.

URLPMID:24830244 [本文引用: 2]

Using two summer maize (Zea mays L.) varieties Zhengdan 958 and Xianyu 335, a field experiment was conducted to study the regulatory effects of row-spacing (equidistant row and narrow-wide row) and plant-spot spacing arrangement (1 plant per spot, 2 plants per spot, 3 plants per spot) on grain yield components, canopy structure and photosynthetic characteristics after anthesis under plant population density 7.5 x 10(4) plants x hm(-2). Moreover, the characters of grain-filling were simulated by Richards' model. The results suggested that yield, dry matter accumulated, crop growth rate, grain-filling rate, canopy photosynthesis capacity were higher under wide-narrow row than under equidistant row, and were higher for 2 plants per spot than for 1 or 3 plants per spot. The highest maize yields (13.12 and 13.72 t x hm(-2) for Zhengdan 958 and Xianyu 335, respectively) were observed under wide-narrow row with 2 plants per spot. Under this pattern, internal illumination condition of the canopy, net photosynthetic rate and leaf area index were improved, and the contradiction between the plant individual and group was alleviated. Meanwhile, grain-filling capacity was promoted and accumulated amount of dry matter was elevated ultimately. It was concluded that wide-narrow pattern with 2 plants per spot is an effective cultivation pattern to increase maize yield in Huang-Huai-Hai Plain.

WEI

S S

, WANG

X Y

, DONG

S T

. Effects of row spacing on canopy structure and grain-filling characteristics of high-yield summer maize
Chinese Journal of Applied Ecology, 2014, 25(2): 441-450. (in Chinese)

URLPMID:24830244 [本文引用: 2]

黄振喜, 王永军, 王空军, 李登海, 赵明, 柳京国, 董树亭, 王洪军, 王军海, 杨今胜. 产量15000 kg·ha^-1以上夏玉米灌浆期间的光合特性
中国农业科学, 2007, 40(9): 1898-1906.

URL [本文引用: 1]

【Objective】It is very important to study photosynthesis of super high-yielding maize hybrids, so a field trail was conducted to research the relation to photosynthetic traits and yield of over-15000 kg ha-1 summer maize hybrids during grain filling period. 【Method】Three summer maize hybrids (XY335, DH3632 and DH3806) were planted at 78000 plants ha-1 in National Corn Project Technology Research Center (Shandong) randomly. Above-ground biomass partitioning and photosynthetic characteristics of ear leaves were investigated to evaluate yield formation of three super high-yielding maize hybrids during grain filling period.【Result】Yields of three-type maize hybrids were over 15000 kg ha-1, and yield of XY335 was higher than that of DH3632 and DH3806 significantly (P＜0.05). Characteristic of grain filling analyzed by Richards equation showed XY335 had the higher grain-filling rate, the longer active growing period, and it reached the maximum grain-filling rate earlier than DH3632 and DH3806. The result indicated grain-filling traits like XY335 was favorable to high yield in the experiment. The leaves’ photosynthetic physiology quantity of XY335 was highest of the three-type hybrids. XY335 had high net photosynthetic rate (Pn), PEPCase activity, RuBPCase activity and chlorophyll a/b value after anthesis, and the leaf area index (LAI) and soluble protein content decreased slowly from 20d and 30d after flowering, respectively. 【Conclusion】To obtain 15000 kg ha-1 of super high-yielding breeding and cultivation in practice, we need to improve the leaves photosynthetic physiology quantity to maintain high grain-filling rate and long active growing period after anthesis, enhance the solar energy use efficiency.

HUANG

Z X

, WANG

Y J

, WANG

K J

, LI

D H

, ZHAO

, LIU

J G

, DONG

S T

, WANG

H J

, WANG

J H

, YANG

J S

. Photosynthetic characteristics during grain filling stage of summer maize hybrids with high yield potential of 15000 kg·ha^-1
Scientia Agricultura Sinica, 2007, 40(9): 1898-1906. (in Chinese)

URL [本文引用: 1]

D L

, XIE

R Z

, NIU

X K

, LI

S K

, LONG

H L

, LIU

Y E

. Changes in the morphological traits of maize genotypes in China between the 1950 and 2000
European Journal of Agronomy, 2014, 58: 1-10.

DOI:10.1016/j.eja.2014.04.001 URL [本文引用: 1]

Maize (Zea mays L.) morphological traits influence light attenuation within the canopy, and, ultimately, yield. The objectives of this 3-year field study were to: (i) examine the morphological characteristics of specific genotypes using varieties of maize that were widely used in Chinese agriculture from the 1950s to the 2000s; (ii) assess the canopies and yields of maize populations in relation to changes in their morphological characteristics. There were significant decrease on the ear ratio, center of gravity height and leaf angle with improved genotypes regardless of plant density. However, the ear leaves and adjacent leaves appeared to be longer in improved maize varieties. The mean leaf orientation value (LOV) and individual LOVs increased considerably during the time series of the genotypes, but more obvious changes in LOV occurred in the uppermost leaves. The average leaf area (LA) per plant and LA on the ears increased significantly from the 1950s to the 2000s. At the optimum density, current hybrid's canopy architecture was more compact, having short plant height and more upright leaf. The SDLA above or under ear significantly increased with improving genotypes, mainly due to new hybrids allowing the use of more individuals per area and thus increasing leaf area index (LAI). At the highest plant density, new hybrids had the rates of light transmittance (0.04-0.05), low attenuation coefficient (K=0.47) and gained the highest yield. Leaf angle and LOV were highly correlated with TPAR/IPAR on ear, K, grain yield. Consequently, yield improvement in maize was probably a result of increased plant density tolerance through dependence on changes in leaf orientation characteristics. (C) 2014 Elsevier B.V.

[31]

张旺锋, 王振林, 余松烈, 李少昆, 曹连莆, 任丽彤. 膜下滴灌对新疆高产棉花群体光合作用、冠层结构和产量形成的影响
中国农业科学, 2002, 35(6): 632-637.

URL [本文引用: 1]

通过对新疆膜下滴灌棉花节水高产的机理探讨表明 ,限量滴灌 (为新疆目前大田膜下滴灌暂定 375m3 /ha滴水定额的 2 /3)棉田土壤水分亏缺 ,群体光合速率降低 ;群体呼吸速率及群体呼吸占群体总光合的比值在盛花期较高 ,进入盛铃期以后群体呼吸又显著低于适量滴灌棉花 ;叶面积指数低 ,叶片平均倾斜角度大 ,群体散射辐射透过系数和群体直射辐射透过系数增加 ,对光能的截获率降低 ;光合物质累积少 ,但分配到生殖器官中的比例上升快。不同品种对滴水量的反应差异较大 ,新陆早 6号对限量滴灌反应不敏感 ,籽棉产量与适量滴灌棉田差异不显著 ;而新陆早 8号对限量滴灌反应较敏感 ,籽棉产量明显低于适量滴灌棉田。因此 ,在限量滴灌条件下选择新陆早6号种植较适宜 ;在新疆开展抗旱品种选育 ,实行节水滴灌是有潜力的

ZHANG

W F

, WANG

Z L

, YU

S L

, LI

S K

, CAO

L P

, REN

L T

. Effect of under-mulch-drip irrigation on canopy apparent photosynthesis, canopy structure and yield formation in high-yield cotton of Xinjiang
Scientia Agricultura Sinica, 2002, 35(6): 632-637. (in Chinese)

URL [本文引用: 1]

刘广周. 产量潜力22.5 t hm^-2玉米理想株型及群体结构研究
[D]. 北京: 中国农业科学院, 2019.

[本文引用: 1]

LIU

G Z

. Research on maize (Zea mays L.) ideotype and canopy structure with yield potential of 22.5 t hm^-2
[D]. Beijing: Chinese Academy of Agricultural Sciences, 2019. (in Chinese)

[本文引用: 1]

[33]

徐克章, 武志海, 王珍. 玉米群体冠层内光和CO₂分布特性的初步研究
吉林农业大学学报, 2001, 23(3): 9-12.

URL [本文引用: 1]

3种株型玉米品种冠层内光量子密度的日变化呈早晚低、中午高的单峰曲线变化。冠层内光量子密度的分布为上层叶>中层叶>下层叶。高产群体穗位叶透光率大于25%,截光率在95%以上。冠层内CO_(2)浓度的日变化呈“W”型,早晚高,上午、下午低,中午稍有一定回升。冠层内CO_(2)浓度变化为下层叶>上层叶>中层叶。高产群体中上层CO_(2)浓度较接近,一般为320-330#mu#mol/mol。

K Z

, WU

Z H

, WANG

. The primary study on the distribution character of irradiance and CO₂ of maize canopies
Journal of Jilin Agricultural University, 2001, 23(3): 9-12. (in Chinese)

URL [本文引用: 1]

胡旦旦, 张吉旺, 刘鹏, 赵斌, 董树亭. 密植条件下玉米品种混播对夏玉米光合性能及产量的影响
作物学报, 2018, 44(6): 920-930.

DOI:10.3724/SP.J.1006.2018.00920 URL [本文引用: 1]

During the 2016 and 2017 growing seasons in Shandong, a province in the North China Plain, using Zhengdan 958 and Denghai 605 for five treatments, including M (random sowing after mixing in the same proportion), 1:1 (raw ratio of ZD958 to DH605 is 1:1), 2:2 (raw ratio of ZD958 to DH605 is 2:2), and two monoculture treatments (SDH605 and SDH605). This experiment was conducted to explore the effects of mixed-cropping on grain yield, amount of dry matter of groups, net photosynthetic rate, anti-oxidative metabolism, canopy structure of summer maize under a density of 82 500 plants ha ^-1. The two-year results showed that mixed-cropping significantly improved canopy light transmittance, leaf area index, chlorophyll content, net photosynthetic rate and dry matter accumulation. Superoxide dismutase (SOD), peroxidase (POD) activities and soluble protein content increased significantly, but the content of MDA decreased under mixed-cropping. The grain yield of summer maize increased significantly under mixed-cropping, due to the increase in grains per spike and 1000-kernel weight. Compared with SZD958 and SDH605, the two-year average grain yields of M, 1:1, 2:2 increased by 11.47%, 8.70%, 8.48% and 9.30%, 6.42%, 6.20%, respectively. There were no significant difference among M, 1:1 and 2:2 treatments. Mixed-cropping formed high-efficiency canopy structure, created better aeration and transmittance conditions, delayed leaf senescence, slowed down the decrease of leaf area index and chlorophyll content after anthesis, maintained higher net photosynthetic rate and increased dry matter accumulation, eventually resulted in the higher grain yield of summer maize. It is concluded that mixed-cropping with reasonable varieties can significantly increase the yield of close planting summer maize, which is one of the optional cultivation patterns to increase maize yield in the Yellow-Huaihe-Haihe Rivers Plain．

D D

, ZHANG

J W

, LIU

, ZHAO

, DONG

S T

. Effects of mixed-cropping with different varieties on photosynthetic characteristics and yield of summer maize under close planting condition
Acta Agronomica Sinica, 2018, 44(6): 920-930. (in Chinese)

DOI:10.3724/SP.J.1006.2018.00920 URL [本文引用: 1]

柏延文, 杨永红, 朱亚利, 李红杰, 薛吉全, 张仁和. 种植密度对不同株型玉米冠层光能截获和产量的影响
作物学报, 2019, 45(12): 1868-1879.

DOI:10.3724/SP.J.1006.2019.93011 URL [本文引用: 1]

The objective of this study was to clarify the relationship between light interception in canopy and dry matter production and grain yield in different plant types of maize. The response of morphological characteristics, canopy light distribution, grain filling parameters and dry matter accumulation were studied using three different maize hybrids Shaandan 609 (SD609, compact), Qinlong 14 (QL14, semi-compact), and Shaandan 8806 (SD8806, flat) with four plant densities (4.5×10 ⁴, 6.0×10 ⁴, 7.5×10 ⁴, and 9.0×10 ⁴plants hm ^-2) in the field from 2016 to 2017. The average yields of SD609, QL14, and SD8806 were 12,176, 9624, and 8533 kg hm ^-2, respectively, within two years, reaching high yields under 9.0×10 ⁴, 7.5×10 ⁴, and 6×10 ⁴ plants hm ^-2, with the yield increase of 26.9%, 20.4%, and 19.7% compared with those under 4.5×10 ⁴ plants hm ^-2, respectively. With the increase of plant density, leaf area decreased, but LAI and leaf orientation value increased. The middle leaves of SD609 were more upright and larger than those of QL14 under 9×10 ⁴ plants hm ^-2. With increasing plant density, D_max (days to the maximum grain-filling rate), W_max (kernel weight at the maximum grain filling rate), G_max (maximum grain-filling rate), G_ave (average grain-filling rate) and P (active filling period) decreased, the D_max for SD609 was 1.4 days and 3.0 days earlier than that of QL14 and SD8806, and the W_max and P were higher than those of SD636 (0.3 g and 3.3 d) and SD8806 (1.1 g and 5.4 d), respectively. The dry matter accumulation after silking and the contribution of dry matter transportation to grain yield increased and then decreased with the increase of plant density, the accumulation, transportation and contribution to grain of dry matter after anthesis were higher in SD609 than QL14 (5.1%, 36.0%, 33.5%) and SD8806 (26.6%, 46.7%, 59.1%). The light interception in the ear canopy was significantly correlated with yield (r = 0.631, P < 0.05), the dry matter accumulation after silking (r = 0.661) and average grain filling rate (r = 0.859) at P < 0.01. Thus, compared with QL14 and SD8806, SD609 could regulate the mid and upper leaves more vertical under close planting, improve the light distribution in the mid and lower canopy, maintain a higher area of green leaves, delay the senescence of canopy leaves, increase dry matter accumulation after anthesis and grain filling rate, so obtain a higher grain yield.

BAI

Y W

, YANG

Y H

, ZHU

Y L

, LI

H J

, XUE

J Q

, ZHANG

R H

. Effect of planting density on light interception within canopy and grain yield of different plant types of maize
Acta Agronomica Sinica, 2019, 45(12): 1868-1879. (in Chinese)

DOI:10.3724/SP.J.1006.2019.93011 URL [本文引用: 1]

杨克军, 萧常亮, 李明, 李振华. 栽培方式与群体结构对玉米生长发育及产量的影响
黑龙江八一农垦大学学报, 2005, 17(4), 9-12.

[本文引用: 1]

YANG

K J

, XIAO

C L

, LI

Z H

. Study on the influence of cultivation methods and community construction to growth and yield of corn
Journal of Heilongjiang Bayi Agricultural University, 2005, 17(4): 9-12. (in Chinese)

[本文引用: 1]