姜英^,1, 王峥宇¹, 廉宏利¹, 王美佳¹, 苏业涵¹, 田平¹, 隋鹏祥¹, 马梓淇¹, 王英俨¹, 孟广鑫¹, 孙悦¹, 李从锋², 齐华^,11沈阳农业大学农学院,沈阳 110866
²中国农业科学院作物科学研究所,北京 100081

Effects of Tillage and Straw Incorporation Method on Root Trait at Silking Stage and Grain Yield of Spring Maize in Northeast China

JIANG Ying^,1, WANG ZhengYu¹, LIAN HongLi¹, WANG MeiJia¹, SU YeHan¹, TIAN Ping¹, SUI PengXiang¹, MA ZiQi¹, WANG YingYan¹, MENG GuangXin¹, SUN Yue¹, LI CongFeng², QI Hua^,11College of Agronomy, Shenyang Agricultural University, Shenyang 110866
²Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081

通讯作者: 齐华,E-mail： qihua10@syau.edu.cn

责任编辑: 杨鑫浩
收稿日期:2020-04-9接受日期:2020-07-11网络出版日期:2020-08-01

基金资助:

国家重点研发计划.2016YFD0300103 国家自然科学基金.31901471 辽宁省科学技术计划.2019JH2/10200004

Received:2020-04-9Accepted:2020-07-11Online:2020-08-01
作者简介 About authors
姜英,E-mail： jiangying@syau.edu.cn。















摘要
【目的】针对东北春玉米主产区秸秆处理的突出矛盾,优化秸秆还田方式对促进该区农业绿色可持续发展意义深远。本文研究了耕作和秸秆还田方式对春玉米根系形态及分布特征、干物积累和产量的影响,旨在为该区域耕作措施调整、实现秸秆还田维持耕地农业生产提供理论依据。【方法】2017—2018年在辽宁沈阳进行田间试验,采用二因素随机区组设计,分别设置秸秆全层翻耕还田（PTS）、秸秆条带翻耕还田（PSS）、秸秆全层旋耕还田（RTS）和秸秆条带旋耕还田（RSS）4个处理。分析不同耕作和秸秆还田方式下春玉米根长、根干重及其空间分布、植株地上部干物质积累动态和产量性状的差异。【结果】耕作和秸秆还田方式对吐丝期春玉米根长及其分布、根干重和比根长影响显著。在0—30 cm垂直土层,PTS处理根长2017年和2018年分别高出其他处理7.9%—43.2%和17.3%—41.5%;在30—60 cm垂直土层,秸秆条带还田（PSS和RSS处理）根长较秸秆全层还田（PTS和RTS处理）平均高出20.1%和20.3%;以植株为中心,PTS处理距植株0—10 cm的根长分布最高,RTS处理最低。根干重在0—10 cm土层表现为RTS处理最低,PTS、PSS、RSS处理2年平均高出36.5%、59.6%和17.3%。PTS处理在0—20 cm土层2年均具有最高比根长,2017年和2018年较其他处理分别高出8.7%—73.8%和14.3%—44.7%。不同处理根表面积的空间分布差异明显,PTS和RSS处理在0—30 cm土层具有较高的根表面积,在水平和垂直方向具有更广的根表面分布。耕作和秸秆还田方式对拔节期、吐丝期和成熟期春玉米地上部干物质积累的影响差异显著,RTS处理较其他处理降低了拔节期茎鞘和地上部总干物重,平均达15.5%—19.2%;PTS处理成熟期果穗和地上总干物重比其他处理提高3.6%—12.3%和2.7%—12.4%,其次为PSS和RSS处理,RTS处理最低。耕作和秸秆还田方式处理显著影响春玉米穗数和籽粒产量,与RTS处理相比,PTS、PSS和RSS处理2年产量平均高出8.3%、7.9%和5.8%;RTS穗数2017年和2018年较其他处理显著降低2.9%—9.1%和7.0%—9.7%。【结论】适当的耕作和秸秆还田方式有利于促进作物根系形态发育及耕层空间分布,促进干物质积累和分配特征优化及成熟期干物质向果穗的分配,达到提高春玉米产量的目的,在本研究区域中推荐秸秆条带翻耕还田方式。
关键词： 秸秆还田;春玉米;根系分布;籽粒产量

Abstract
【Objective】In view of the prominent contradiction of straw utility, the optimization of straw returning method is significant for promoting the green and sustainable development of agriculture in northeast China, where is the main production areas of spring maize. In this study, the effects of tillage and straw incorporation approaches on the morphology and distribution characteristics of root, dry matter accumulation and yield of spring maize were investigated to provide a theory basis for optimizing tillage and straw incorporation measures to maintain agricultural production.【Method】The field experiment was carried out in Shenyang, Liaoning province in 2017 and 2018. The two-factor random zone group design was adopted to set up four treatments, including straw incorporation with full-thickness plough tillage (PTS), straw incorporation with strip plough tillage (PSS), straw incorporation with full-thickness rotary tillage (RTS), and straw incorporation with strip rotary tillage (RSS). Under different tillage and straw incorporation methods, the differences of root length, root dry weight, their spatial distribution in soil, dry matter accumulation dynamics and yield characters of spring maize were analyzed.【Result】Tillage and straw incorporation methods had significant effects on root length and distribution as well as dry weight and specific root length of spring maize at silking stage. In the vertical soil layer of 0-30 cm, the root length of PTS treatment was 7.9%-43.2% and 17.3%-41.5% higher than other treatments, respectively. In the vertical soil layer of 30-60 cm, root length under strip straw incorporation (PSS and RSS) treatments was average 20.1% and 20.3% higher than those under full-thickness straw incorporation (PTS and RTS) treatments, respectively. Centering on maize plant, the horizontal distribution of root length in soil showed that PTS treatment was the highest and RTS treatment was the lowest in 0-10 cm away from the plant. The lowest root dry weight was observed from RTS treatment, PTS, PSS and RSS treatments presented 36.5%, 59.6% and 17.3% higher root dry weight in the 0-10 cm soil layer, respectively. PTS treatment obtained the highest specific root length in 0-20 cm soil layers, with 8.7%-73.8% and 14.3%-44.7% more than those under other treatments. The spatial distribution of root surface area was significantly different among treatments. PTS and RSS treatments had higher root surface area in 0-30 cm soil layer and better root surface distribution in horizontal and vertical directions. The effects of tillage and straw incorporation methods on the accumulation of dry matter in shoot of spring maize at jointing, silking and maturity stages were significant. Compared with other three treatments, RTS reduced the average dry matter weight of stem+sheath and total shoot weight by 15.5% to 19.2% at jointing stage. The weight of ear and shoot dry matter in maturity stage under PTS treatment was 3.6%-12.3% and 2.7%-12.4% higher than those under other treatments, followed by PSS and RSS treatments, and RTS treatment was the lowest. Tillage and straw incorporation methods significantly affected the number of ears and grain yield of spring maize. PTS, PSS, and RSS treatments obtained average 8.3%, 7.9%, and 5.8% higher grain yield than that under RTS treatments in 2017 and 2018. RTS significantly reduced the number of ears by 2.9%-9.1% and 7.0%-9.7%, compared with other three treatments.【Conclusion】Proper tillage and straw returning methods were conducive to promoting the morphological development of crop root and its spatial distribution in the tilled soil layer, optimizing of dry matter accumulation and distribution characteristics, and the distribution of dry matter to ear at maturity, so as to increase the yield of spring maize. In summary, the straw strip returning with plough tillage was recommended in the study area.
Keywords：straw incorporation;spring maize;root distribution;grain yield


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本文引用格式
姜英, 王峥宇, 廉宏利, 王美佳, 苏业涵, 田平, 隋鹏祥, 马梓淇, 王英俨, 孟广鑫, 孙悦, 李从锋, 齐华. 耕作和秸秆还田方式对东北春玉米吐丝期根系特征及产量的影响[J]. 中国农业科学, 2020, 53(15): 3071-3082 doi:10.3864/j.issn.0578-1752.2020.15.008
JIANG Ying, WANG ZhengYu, LIAN HongLi, WANG MeiJia, SU YeHan, TIAN Ping, SUI PengXiang, MA ZiQi, WANG YingYan, MENG GuangXin, SUN Yue, LI CongFeng, QI Hua. Effects of Tillage and Straw Incorporation Method on Root Trait at Silking Stage and Grain Yield of Spring Maize in Northeast China[J]. Scientia Acricultura Sinica, 2020, 53(15): 3071-3082 doi:10.3864/j.issn.0578-1752.2020.15.008

0 引言

【研究意义】我国农作物秸秆产量超过7亿吨,其中玉米秸秆占比高达37.5%,而东北三省玉米秸秆约占全国玉米秸秆总产量的20%^[1],因此,如何合理利用东北地区玉米秸秆成为区域农业绿色发展面临的重大问题。近年来,秸秆直接还田成为东北玉米主产区提升耕地质量、降低生态成本的重要措施^[1,2]。东北地区传统的玉米秸秆还田方式包括深翻秸秆还田、旋耕秸秆还田和秸秆覆盖还田等,但该区域冬春季节气温较低、降水偏少不利于秸秆腐解^[3,4]。一方面,秸秆腐解与作物播种和生长同期进行,腐解过程与作物生长存在氮素竞争等问题^[5,6]。另一方面,秸秆还田条件下的耕层土壤松散,影响种子发芽（着根）和作物抗倒伏能力^[7,8]。因此,在东北春玉米产区突破传统秸秆还田方式的技术瓶颈,探索适宜的秸秆还田方式对实现区域农业绿色发展具有重要的现实意义。【前人研究进展】实际生产中,秸秆还田过程往往伴随着相应的耕作措施进行,如秸秆翻耕还田、秸秆旋耕还田等,结合多种耕作形式的秸秆还田措施得到了诸多尝试和研究^[9]。一方面,耕作措施对耕层土壤团聚体结构、土壤渗水能力、土壤养分构成及土壤微生态环境具有重要影响^{[10,11,12,13]};另一方面,不同秸秆还田方式决定了秸秆对耕层土壤物理属性和腐解过程的影响差异,间接地影响耕层土壤理化性质和微生态环境。研究表明,秸秆还田量（半量、全量等）和还田方式（翻埋、混拌、覆盖等）决定了秸秆在耕层土壤中的分布状态和环境,这些因素导致了秸秆还田影响作物生长环境的差异性^{[4, 14-15]}。耕作和秸秆还田方式及其交互效应对作物生产影响的差异性,在作物生长和籽粒产量等方面不尽相同。殷文等^[16,17]通过研究河西绿洲灌区不同耕作和秸秆还田方式对小麦和玉米生产的影响,表明小麦前茬免耕高留茬覆盖较翻耕秸秆高留茬或低茬收割还田,对玉米籽粒产量提高作用显著,并表现出对干物质积累的促进作用;而玉米前茬少耕秸秆高留茬立茬还田、少耕秸秆高留茬覆盖还田较翻耕高留茬还田小麦产量提高显著,说明不同耕作和秸秆还田方式对作物产量的作用效果具有差异性。然而,赵亚丽等^[9]在研究黄淮海地区麦-玉轮作系统中耕作和秸秆还田效应发现,较秸秆不还田处理,结合深松和深耕的秸秆还田处理显著提高了周年作物干物质积累及产量,但深耕和深松秸秆还田的处理间无显著差异。近来,隋鹏祥等^[3]在东北春玉米区对秸秆旋耕和翻耕还田进行比较,研究发现两者对春玉米籽粒产量及氮素积累无显著差异,但对地上部干物质积累和氮素转运具有显著影响。穆心愿等^[18]等认为,秸秆还田对作物生长及产量的影响受到耕作方式、还田方式、气候条件、土壤类型及其他农艺管理措施等综合调控,研究结果总体表现出较大的差异性。事实上,耕作和秸秆还田处理调控作物根系发育是影响作物地上部生长和产量形成不容忽视的重要环节。MU等^[19]和YOU等^[20]分别在我国华北和东北地区进行了相关研究,结果表明结合秸秆还田的翻耕或深松耕作处理显著改善作物根系生长特征,并且不同耕作和秸秆还田方式对作物根系在不同土层中的分布有显著影响;而SUI等^[21]研究也发现,翻耕和旋耕秸秆还田通过调控根系生长进而影响玉米产量。随着国家一系列鼓励秸秆还田政策的提出,多种形式的耕作和秸秆还田措施不断出现。研究发现,秸秆条带还田能够改善作物根际水分和养分的空间分布等特点^[22,23,24]。因此,与传统的全层耕作和秸秆还田方式相比,秸秆条带还田方式如何影响作物根系生长的空间分布,进而影响作物地上部生长发育及产量形成值得深入研究。【本研究切入点】耕作和秸秆还田方式能够改善耕层土壤的诸多理化性质,改变耕层土壤中水分、养分等空间分布条件,最终影响作物生长和籽粒产量。由于耕作和秸秆还田方式对春玉米生长及生产仍未能得到一致而系统的结论,在东北春玉米产区秸秆还田大力推行的背景下,不同耕作的秸秆条带还田与全层还田条件下作物生长特性及产量响应仍值得深入研究。【拟解决的关键问题】本研究着眼于东北春玉米主产区的秸秆还田问题,通过研究翻耕和旋耕条件下,全层和条带秸秆还田方式对春玉米吐丝期根系生长空间分布、干物质积累及作物产量的变化规律,明确春玉米根系构造和物质生产对耕作和秸秆还田方式的响应,以期为东北地区春玉米秸秆还田生产实践提供科学依据。

1 材料与方法

1.1 试验区概况

试验于2017—2018年在沈阳农业大学作物科学试验基地进行（123°33′E,41°49′N）。该试验区属于典型温带大陆性季风气候,年平均气温8.7℃,年平均降水量714 mm,全年无霜期155—180 d,一年一熟制,雨养旱作栽培,主要种植作物为春玉米。2017和2018年玉米生长季总降雨量分别为388.4 mm和430.4 mm,玉米生育期的日降水量和平均气温变化情况如图1所示。供试土壤类型为棕壤,0—20 cm土层基本理化性状为有机碳10.02 g·kg^-1、全氮1.13 g·kg^-1、速效磷16.19 mg·kg^-1、速效钾128.11 mg·kg^-1、pH 5.60。

图1

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图12017-2018年作物生育期日降雨量和日平均气温变化

Fig. 1Mean daily precipitation and air temperature during crop growth stage in 2017 and 2018

1.2 试验设计

试验采用二因素随机区组设计,耕作处理分为翻耕、旋耕方式,秸秆还田处理分为全层还田和条带还田方式,试验共4个处理,分别为秸秆全层翻耕还田（PTS）、秸秆条带翻耕还田（PSS）、秸秆全层旋耕还田（RTS）和秸秆条带旋耕还田（RSS）。每个处理设置3次重复,随机区组排列。试验小区行长12 m,行宽0.6 m,10行区,小区面积72 m²。2017—2018年均为上季作物收获后进行耕作与秸秆还田处理,将秸秆粉碎后（5 cm左右）全量还田。全层翻耕和旋耕还田采用机械处理;条带旋耕秸秆还田为混拌式,而条带翻耕秸秆还田为翻埋式,在行间分别挖出宽30 cm、深度为15 cm（旋耕）和30 cm（翻耕）的沟槽进行秸秆还田,如图2所示。供试玉米品种“郑单958”,种植密度67 500株/hm²。播种时一次性施入氮肥（N）75 kg·hm^-2、磷肥（P₂O₅）75 kg·hm^-2和钾肥（K₂O）85 kg·hm^-2作基肥,在玉米拔节期追施氮肥（N）150 kg·hm^-2,其他病、虫、草管理按照当地常规方式进行。

图2

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图2试验处理田间模式图

PTS：秸秆全层翻耕还田;PSS：秸秆条带翻耕还田;RTS：秸秆全层旋耕还田;RSS：秸秆条带旋耕还田。下同
Fig. 2Diagram of experimental treatments in the field

PTS: Straw incorporation with full-thickness plough tillage; PSS: Straw incorporation with strip plough tillage; RTS: Straw incorporation with full-thickness rotary tillage; RSS: Straw incorporation with strip rotary tillage. The same as below

1.3 测定指标及方法

1.3.1 土壤基础理化性质测定 于2016年秋季试验前,以“S”形取样法采集试验田0—20 cm土壤样品带回室内,土样室内风干后,经研磨并通过20目和100目筛,测定土壤基础理化性质。土壤有机碳和全氮含量采用元素分析仪（EA 3000）测定;速效磷含量采用钼锑抗比色法测定,速效钾含量采用火焰光度法测定^[25];土壤pH采用电子pH计（PHSJ-3F）测定土液比为1:2.5浸提液所得^[25]。

1.3.2 根系取样及样品测定 在2017和2018年玉米吐丝期,选取各小区长势均匀的3株玉米,采用Monilith 3D法收集根系^[26]。取样土体总体积为长60 cm×宽24 cm×深60 cm,然后细分为36个10 cm×24 cm×10 cm的土体,将每个土体中所有根系仔细捡出、去杂后清洗干净,置于-20℃备测。利用扫描仪（EPSON Perfection V800）进行根系样品图片扫描,运用根系分析程序（WinRHI 2.0 Pro 2012）获得根系相关数据,计算总根长和比根长^[23]。分别在0—30 cm和30—60 cm土层测定垂直根长分布;以玉米植株为中心测定距离0—10、10—20及20—30 cm水平根长分布。同时,将扫描完的根系按每10 cm土层分装收好,置于80℃烘箱内烘干至恒重,使用万分之一天平称重。

1.3.3 作物地上部干物质量、产量及产量构成因素 于玉米拔节期、吐丝期和成熟期,每个小区随机选取长势一致的3株玉米,进行地上部植株取样。植株样品分为叶片、茎鞘、果穗（吐丝期、成熟期）,经105℃杀青30 min,80℃烘干至恒重后称重,测定各部分干物质量。成熟期各小区选取中间3行统计收获穗数并实收测产,依照计算后的平均穗重,选取10个果穗进行考种,测定穗粒数和百粒重。采用谷物水分测定仪（PM-8188-A）测定籽粒含水量,折算为14%含水量的玉米籽粒产量。

1.4 数据处理

采用Microsoft Excel 2016进行数据处理,SPSS 20.0进行处理间方差分析和显著性检验（Duncan）,Origin 9.0和Surfer 8.0软件作图。

2 结果

2.1 根长及其分布

耕作和秸秆还田方式对吐丝期春玉米根系垂直根长分布、水平根长分布和总根长有显著影响,且两者交互效应显著（表1,P<0.05）。从根长垂直分布看,在0—30 cm土层,PTS处理根长显著高于其他处理,2017和2018年分别高出7.9%—43.2%和17.3%— 41.5%;在30—60 cm土层,秸秆条带还田（PSS和RSS处理）根长明显高于秸秆全层还田（PTS和RTS处理）,2年平均高出25.2%和12.3%。从根长水平分布可知,根长分布表现为以植株为中心由近及远递减,距植株0—10 cm范围根长分布表现出PTS处理最高,RTS处理最低;与旋耕处理（RSS、RTS）相比,翻耕处理（PSS、PTS）在距植株10—20 cm根长分布2年平均提高了17.0%和9.8%。总根长2年均表现为PTS>PSS>RSS>RTS,2年范围分别在397.4—535.1 m和649.7—780.9 m,2017年作物在垂直和水平方向的整体根长分布水平低于2018年。

Table 1
表1
表1耕作和秸秆还田方式对吐丝期春玉米根长及其分布的影响
Table 1Effects of tillage and straw incorporation methods on root length and its distribution of spring maize at silking stage (m)

年份 Year	处理 Treatment	垂直根长分布 Vertical root length distribution			水平根长分布 Horizontal root length distribution			总根长 Total root length
		0-30 cm	30-60 cm	0-10 cm		10-20 cm	20-30 cm
2017	PTS	454.8a	80.3b	290.7a		157.7a	80.3b	535.1a
	PSS	421.4a	102.5a	281.4a		133.5b	102.4a	523.9a
	RTS	317.6b	79.8b	209.3b		105.2c	82.9b	397.4b
	RSS	383.2ab	111.5a	280.3a		136.6b	99.8a	494.7a
2018	PTS	508.6a	272.4c	422.8a		189.7ab	168.4a	780.9a
	PSS	433.5b	301.0ab	369.2c		216.2a	149.1b	734.5b
	RTS	359.8d	289.9b	349.7d		169.3b	130.7b	649.7c
	RSS	391.4c	339.9a	381.6a		196.8ab	152.9a	731.3b
方差分析（F值）ANOVA (F-value)
T		9.11**	7.05	0.25*		0.17**	21.25	35.65**
S		3.17*	1.98**	9.66*		2.39*	1.89**	26.36**
T×S		0.275**	8.14*	1.37*		1.94*	9.21*	5.32**

PTS：秸秆全层翻耕还田;PSS：秸秆条带翻耕还田;RTS：秸秆全层旋耕还田;RSS：秸秆条带旋耕还田;T：耕作因素效应;S：秸秆还田方式效应;T×S：耕作与秸秆还田方式交互效应。不同字母表示处理间在P<0.05水平差异显著。*,**分别表示在0.05,0.01水平差异显著。下同
PTS: Straw incorporation with full-thickness plough tillage; PSS: Straw incorporation with strip plough tillage; RTS: Straw incorporation with full-thickness rotary tillage; RSS: Straw incorporation with strip rotary tillage; T: tillage factor; S: Straw incorporation approaches factor; T×S: Interaction effects of tillage and straw incorporation approaches. Different letters in the same column indicate significant differences between treatments at 0.05 level. *and** indicate significant difference at 0.05 and 0.01 levels. The same as below

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2.2 根干物质

耕作和秸秆还田方式对吐丝期春玉米不同土层根干重的影响如图3所示,0—60 cm土层根干重随着土层深度增加呈递减趋势。2017年,各处理对0—60 cm土层根干重有显著影响（P<0.05）。在0—10 cm土层,RTS处理根干重最低,PTS、PSS、RSS处理分别高出36.5%、59.6%和17.3%,而在20— 60 cm土层PTS处理根干重最高;各处理在0—10 cm和20—60 cm土层每株春玉米根干重为5.16—8.57 g和0.16—2.23 g。2018年,各处理对0—50 cm土层根干重有显著影响（P<0.05）,对50—60 cm土层根干重影响不显著。与2017年类似,在0—10 cm土层,RTS处理根干重表现最低,PTS、PSS、RSS处理分别高出28.2%、32.4%和23.9%;而在20—60 cm土层,各处理根干重未体现明显规律;各处理在0—10 cm和20—60 cm土层每株春玉米根干重为7.10—9.39 g和0.23—3.17 g。

图3

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图3耕作和秸秆还田方式对吐丝期春玉米根干物质的影响

Fig. 3Effects of tillage and straw incorporation methods on root dry weight of spring maize at silking stage

2.3 比根长

在0—60 cm各土层,吐丝期春玉米的比根长受耕作和秸秆还田方式影响显著（P<0.05）,随着土层加深整体呈逐渐增加趋势（图4）。在0—10 cm和10—20 cm土层,PTS处理较其他处理显著提高了比根长（P<0.05）,分别达19.8%—73.8%、8.7%— 51.2%（2017）和21.6%—44.7%、14.3%—41.9%（2018）。在20—30 cm土层,秸秆旋耕处理（RSS、RTS）较秸秆翻耕处理（PSS、PTS）显著降低了比根长,降幅达0.2—1倍。在30—60 cm土层,各处理对春玉米比根长未体现一致的显著性影响,但PSS和RTS处理在40—60 cm土层表现出较高的比根长,最高分别可达79.3 m·g^-1和95.5 m·g^-1。

图4

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图4耕作和秸秆还田方式对吐丝期春玉米比根长的影响

Fig. 4Effects of tillage and straw incorporation methods on specific root length of spring maize at silking stage

2.4 根表面积

耕作和秸秆还田方式对春玉米吐丝期的根表面积空间分布影响如图5所示。2017年,在0—30 cm土层,春玉米根系在不同处理下的空间分布差异明显,RTS处理根表面积最低,在水平方向具有较低的延展;在30—60 cm土层,PTS、RSS处理较RTS、PSS处理具有更高的根表面积,PTS和RSS处理在垂直方向具有更深的根表面积分布特点。2018年,秸秆翻耕（PTS、PSS处理）较秸秆旋耕（RTS、RSS处理）具有更高的根表面积,同时在水平方向根表面积体现出更高的分布;与2017年类似,根表面积主要分布在0—30 cm土层,并且PTS和RSS处理仍表现出在垂直方向具有更深的根表面积分布特点。总体而言,各处理的根表面积具有0—15 cm土层核心分布特点;与2017年相比,2018年根表面积分布线更加密集,说明根表面积随着土层深度和植株水平距离的变化更为明显。

图5

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图5耕作和秸秆还田方式对吐丝期春玉米根系表面积的影响

Fig. 5Effects of tillage and straw incorporation methods on root surface area of spring maize at silking stage

2.5 地上部干物质积累

由表2可见,耕作和秸秆还田方式对春玉米拔节期、吐丝期和成熟期不同植株部位干物质积累的影响显著,而其交互效应对地上部总干物质积累具有显著影响（P<0.05）。在拔节期,RTS处理较其他处理,2017年植株茎鞘和地上部总干物重降低约19.2%和15.5%;而在2018年生长季,RTS处理在叶、茎鞘和地上部总干物重均表现最低,秸秆条带还田（PSS和RSS处理）较秸秆全层还田（PTS和RTS处理）具有较高的茎鞘和地上部总干物重的积累,平均高出6.5%和4.6%。在吐丝期,2017年各处理对地上部总干物重具有显著影响,秸秆条带还田（PSS和RSS处理）较秸秆全层还田（PTS和RTS处理）地上部总干物重平均高出4.1%（P<0.05）;而2018年各处理对茎鞘、果穗和地上部总干物重均具有显著影响（P<0.05）,与2017年拔节期类似,RTS处理的上述指标均低于其他处理。在成熟期,PTS处理果穗和地上部总干物重2年均高于其他处理,分别达3.6%—12.3%（2017）和2.7%—12.4%（2018）,其次为PSS和RSS处理,RTS处理表现为最低。总体看,秸秆翻耕还田（PTS、PSS处理）较旋耕还田（RTS、RSS处理）在春玉米拔节期、吐丝期和成熟期2年均表现为总干物质积累增加,平均幅度为3.9%—5.4%（2017）和3.7%—4.6%（2018）。

Table 2
表2
表2耕作和秸秆还田方式对春玉米生育期地上部干物质的影响
Table 2Effects of tillage and straw incorporation methods on shoot dry matter at jointing, silking and mature stages of spring maize (g/plant)

年份 Year	处理 Treatment	拔节期Jointing stage			吐丝期Silking stage				成熟期Maturity stage
		叶 Leave	茎鞘 Stem	地上部 Shoot	叶 Leave	茎鞘 Stem	果穗 Fruit	地上部 Shoot	叶 Leave	茎鞘 Stem	果穗 Fruit	地上部 Shoot
2017	PTS	35.8a	34.7a	70.5a	48.5a	72.2a	33.8a	154.5a	45.5a	88.9a	220.3a	354.5a
	PSS	36.6a	34.3a	70.9a	50.7a	71.2a	31.2a	153.1a	42.2a	80.6a	209.6b	332.4ab
	RTS	32.5a	29.1b	61.6b	44.5a	68.6a	32.8a	145.9b	37.4b	71.5b	207.2b	315.6b
	RSS	38.0a	34.1a	72.1a	42.1a	76.1a	31.3a	149.5ab	42.9a	85.7a	213.6ab	342.3a
2018	PTS	45.9a	42.5b	88.4ab	46.9a	72.3a	50.4a	169.6a	68.2b	93.5a	233.9a	395.6a
	PSS	41.4a	53.9a	95.3a	48.2a	71.7a	43.5b	163.4a	65.3b	85.7ab	218.6ab	369.6b
	RTS	38.4b	40.8b	79.2b	46.5a	65.4b	41.9b	153.8b	60.8b	80.7b	210.4b	351.9b
	RSS	43.2a	52.9a	96.1a	48.0a	73.8a	44.4b	166.2a	78.1a	86.9ab	220.1a	385.1a
方差分析（F值）ANOVA (F-value)
T		3.15	0.87	10.32	0.69	12.87**	6.37*	19.56*	30.69	2.79*	10.27*	17.32*
S		5..62	5.21*	8.65**	2.16*	8.21	4.15	25.21	12.16	1.17	6.71	4.65**
T×S		2.36	3.56	1.32*	3.65	3.56	0.89	4.01*	9.65	1.68	5.56*	3.32*

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2.6 产量及产量构成因素

耕作和秸秆还田方式对春玉米产量和穗数具有显著影响,两处理因素交互作用显著（P<0.05）,但对穗粒数的影响2年表现不一致（表3）。2017年,各处理间春玉米产量趋势表现为PSS>PTS>RSS>RTS,在9 128.8—9 812.2 kg·hm^-2变化;2018年则表现为PTS>RSS>PSS>RTS,处于9 209.5 kg·hm^-2— 10 100.5 kg·hm^-2范围。各处理对穗数的影响与产量类似,RTS处理较其他处理均表现为显著降低穗数,2年降幅分别在2.9%—9.1%和7.0%—9.7%。2年各处理对春玉米百粒重影响差异不显著（P>0.05）。

Table 3
表3
表3耕作和秸秆还田方式对春玉米产量及其构成因素的影响
Table 3Effects of tillage and straw incorporation approach on grain yield and yield components of spring maize

年份 Year	处理 Treatment	穗数 Ear number (hm-2)	穗粒数 Kernel number	百粒重 100-kernel weight (g)	产量 Yield (kg·hm-2)
2017	PTS	65741a	497a	31.2a	9762.9a
	PSS	66056a	500a	30.5a	9812.2a
	RTS	60574c	495a	29.4a	9128.8b
	RSS	62352b	508a	30.4a	9418.3ab
2018	PTS	67364a	513a	36.8a	10100.5a
	PSS	65741b	509a	35.9a	9981.3a
	RTS	61420c	486b	36.2a	9209.5b
	RSS	66660ab	508a	34.7a	9994.9a
方差分析（F值）ANOVA (F-value)
T		3.341**	0.254	0.126	6.326**
S		0.487*	0.311	0.177	5.275
T×S		0.297**	0.754	0.266	0.222*

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3 讨论

3.1 耕作和秸秆还田方式对春玉米根系生长的影响

随着秸秆还田措施受到鼓励和推广,耕作和秸秆还田对作物根系特征的研究越来越受到重视^[27,28]。耕作和秸秆还田措施对作物根系的影响体现在总体根系形态构造,如根长、根重、比根长和根表面积等。与秸秆旋耕还田相比,秸秆翻耕还田措施能够显著提高0—30 cm农田耕层土壤的物理性能,从而改善作物根系生长环境^[29]。作物根系的生长发育很大程度受到耕层土壤物理结构、水肥供应能力的影响^[29,30]。较好的土壤透气条件有利于作物水肥吸收和延缓根系衰老,从而促进根系在土壤中的生长发育^[31,32]。本研究表明,与秸秆旋耕还田处理相比,春玉米吐丝期秸秆翻耕还田处理的0—30 cm垂直根长、0—10 cm水平根长、总根长和0—20 cm土层根干重普遍较高。这是由于翻耕秸秆还田与旋耕秸秆还田相比,具备了更深层土壤的通气性等优势,从而促进了春玉米的根系生长发育^[21]。无论是翻耕还是旋耕条件,秸秆条带还田区别于秸秆全层还田主要表现为：一是两者对耕层土壤的扰动程度。秸秆翻耕较旋耕、全层较条带还田相比,前者均具有更大的土壤扰动强度;二是秸秆还田后在耕层土壤的垂直分布。翻耕主要使得秸秆被翻埋在25—30 cm土层,旋耕条件下秸秆主要被混拌在0—15 cm土层,旋耕较翻耕还田的秸秆与土壤接触更充分。这些因素使得玉米根系生长所处土壤的物理及养分环境具有明显差异^[22]。前人研究表明,耕作和秸秆条带还田对耕层土壤的养分分布及动态变化具有调控作用,秸秆条带还田促进了水分及养分在30—60 cm土层的分布^[22,23]。这可解释本研究中,秸秆全层旋耕还田较其他处理表现出较低的根长和根干重,以及秸秆条带还田较全层还田在垂直30—60 cm和水平20—30 cm表现出较高水平的根长,说明秸秆条带还田较全层还田具有促进根系向深层土壤生长的作用。

耕作和秸秆还田措施对作物的影响表现在根系于耕层土壤中的空间分布。作物根系空间分布的水肥趋向性较其形态发育更为明显。本研究表明,同秸秆全层还田相比,秸秆条带还田根长和根表面积在水平和垂直的空间分布被普遍提高,在旋耕耕作措施下尤为明显。这是由于同秸秆全层还田相比,秸秆条带还田营造了“虚实相间”耕层土壤结构（图2）,加之等量秸秆还田条件下单位土体秸秆密度增大,这样既避免了秸秆腐解与作物根系生长的养分利用竞争^[12],又为水肥入渗提供了更有利的条件^[33],最终为春玉米根系在耕层土壤中的水平和垂直分布生长创造了有利条件。此外,不同耕作和秸秆还田方式导致秸秆在土壤中腐解过程具有明显差异性,而这过程对土壤的养分动态变化具有重要影响已得到普遍证实^[34]。因此,为了明确秸秆还田影响作物生长发育过程,不同秸秆还田方式下秸秆腐解过程的土壤养分动态变化及其机制值得深入研究。

3.2 耕作和秸秆还田方式对春玉米干物质积累及产量的影响

干物质积累与分配作为“库源”关系的重要表征,是作物籽粒产量形成的重要基础^[35],耕作和秸秆还田对作物干物质积累与转运的研究也受到了足够的重视^[3]。赵亚丽等^[9]研究表明,深松或深耕秸秆还田较常规耕作秸秆还田在华北平原有利于冬小麦-夏玉米两季作物各生育期的干物质累积。而隋鹏祥等^[3]发现,秸秆旋耕还田较翻耕还田处理促进了春玉米地上部干物质积累,但后者具有更高的花前干物质积转移量。说明秸秆还田对作物干物质积累和转移的影响会受到秸秆还田方式和气候等因素的影响。本研究表明,秸秆条带还田较全层还田在春玉米拔节期和吐丝期表现出较高的总干物质积累,这可能由于秸秆条带较全层还田处理更有利于水分向深层入渗分布,促进根系深层分布和养分吸收^[23],最终有利于作物花前干物质积累。而秸秆条带还田促进根系向深层土壤分布的作用在本研究也有类似的体现（表1,图5）。此外,秸秆翻耕处理在各生育期的平均干物质积累高于旋耕处理,主要由于秸秆全层旋耕还田处理（RTS）干物质积累显著低于其他处理造成的,这与隋鹏祥等^[3]研究结果不一致。这可能由于研究区域的气候条件差异（如降水等）,导致耕作方式影响作物干物质积累的作用机制不同,值得深入研究。

前人研究表明,秸秆在翻耕、旋耕以及免耕等条件下还田对玉米籽粒产量影响显著^[20]。本研究也发现,在2017年秸秆翻耕还田下,春玉米籽粒产量显著高于秸秆旋耕还田处理,而在2018年高于秸秆旋耕全层还田处理。从产量构成看,耕作和秸秆还田方式主要影响了春玉米的公顷穗数,导致了最终籽粒产量差异的出现（表3）。这可能由于两方面原因：一是秸秆还田导致下茬作物播种层环境差,影响作物出苗和幼苗生长^[5],这在秸秆旋耕还田条件下尤为明显,本研究秸秆条带旋耕还田较秸秆全层还田公顷穗数和产量有明显提高,说明前者减缓这一弊端,达到同秸秆翻耕还田一致的影响;二是耕作和秸秆还田方式影响春玉米后期抗倒伏特性,本研究在2018年生育后期遭遇强降雨气候（图1）,致使不同程度倒伏发生,尤其在秸秆全层旋耕处理下严重降低了公顷穗数和产量。这与该处理下作物根系在土层中分布较浅（表1）及耕层土壤结构松散密切相关^[33],此外,秸秆翻耕还田较旋耕条件具有作物地上和地下生长发育及物质转移的优势,以及对土壤养分供给能力的改善,更有利于籽粒产量的提高^[21]。

4 结论

在东北春玉米主产区推广秸秆还田背景下,适当的耕作和秸秆还田方式有利于促进作物根系形态发育及耕层空间分布,进一步使得春玉米的干物质积累和分配特征得到优化,提高成熟期干物质在果穗的分配,达到提高春玉米产量的目的。秸秆翻耕还田较秸秆旋耕还田具有更好的根系形态和空间分布,秸秆条带还田较全层还田体现出同样的优势,同时前者表现较高的籽粒产量。因此,推荐秸秆条带翻耕还田为该区域适合的秸秆还田方式。

参考文献 View Option 原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子

[1] 宋大利, 侯胜鹏, 王秀斌, 梁国庆, 周卫. 中国秸秆养分资源数量及替代化肥潜力
植物营养与肥料学报, 2018,24(1):1-21.
[本文引用: 2]

SONG D L, HOU S P, WANG X B, LIANG G Q, ZHOU W. Nutrient resource quantity of crop straw and its potential of substituting
Journal of Plant Nutrition and Fertilizers, 2018,24(1):1-21. (in Chinese)
[本文引用: 2]

[2] KONG L. Maize residues, soil quality, and wheat growth in China. A review
Agronomy for Sustainable Development, 2014,34:405-416.
[本文引用: 1]

[3] 隋鹏祥, 有德宝, 安俊朋, 张文可, 田平, 梅楠, 王美佳, 王沣, 苏思慧, 齐华. 秸秆还田方式与施氮量对春玉米产量及干物质和氮素积累、转运的影响
植物营养与肥料学报, 2018,24(2):316-324.
[本文引用: 5]

SUI P X, YOU D B, AN J P, ZHANG W K, TIAN P, MEI N, WANG M J, WANG F, SU S H, QI H. Effects of straw management and nitrogen application on spring maize yield, dry matter and nitrogen accumulation and transfer
Journal of Plant Nutrition and Fertilizers, 2018,24(2):316-324. (in Chinese)
[本文引用: 5]

[4] 田平, 姜英, 孙悦, 马梓淇, 隋鹏祥, 梅楠, 齐华. 不同还田方式对玉米秸秆腐解及土壤养分含量的影响
中国生态农业学报, 2019,27(1):100-108.
[本文引用: 2]

TIAN P, JIANG Y, SUN Y, MA Z Q, SUI P X, MEI N, QI H. Effect of straw return methods on maize straw decomposition and soil nutrients contents
Chinese Journal of Eco-Agriculture, 2019,27(1):100-108. (in Chinese)
[本文引用: 2]

[5] 杨文钰, 王兰英. 作物秸秆还田的现状与展望
四川农业大学学报, 1999(2):211-216.
[本文引用: 2]

YANG W Y, WANG L Y. Present situation and prospects of returning application of crop straw
Journal of Sichuan Agricultural University, 1999(2):211-216. (in Chinese)
[本文引用: 2]

[6] KUMAR K, GOH K M. Nitrogen release from crop residues and organic amendments as affected by biochemical composition
Communications in Soil Science & Plant Analysis, 34(17/18):2441-2460.
[本文引用: 1]

[7] TURMEL M S, SPERATTI A, BAUDRON F, VERHULST N, GOVAERTS B. Crop residue management and soil health: A systems analysis
Agricultural Systems, 2014,134:6-16.
DOI:10.1016/j.agsy.2014.05.009URL [本文引用: 1]

[8] LI Z Q, ZHAO B Z, OLK D C, JIA Z J, MAO J D, CAI Y F, ZHANG J B. Contributions of residue-C and -N to plant growth and soil organic matter pools under planted and unplanted conditions
Soil Biology and Biochemistry, 2018,120:91-104.
[本文引用: 1]

[9] 赵亚丽, 郭海斌, 薛志伟, 穆心愿, 李潮海. 耕作方式与秸秆还田对冬小麦-夏玉米轮作系统中干物质生产和水分利用效率的影响
作物学报, 2014,40(10):1797-1807.
DOI:10.3724/SP.J.1006.2014.01797URL [本文引用: 3]

ZHAO Y L, GUO H B, XUE Z W, MU X Y, LI C H. Effects of tillage and straw returning on biomass and water use efficiency in a winter wheat and summer maize rotation system
Acta Agronomica Sinica, 2014,40(10):1797-1807. (in Chinese)
DOI:10.3724/SP.J.1006.2014.01797URL [本文引用: 3]

[10] 赵红香, 迟淑筠, 宁堂原, 田慎重, 王丙文, 李增嘉. 科学耕作与留茬改良小麦-玉米两熟农田土壤物理性状及增产效果
农业工程学报, 2013,29(9):113-122.
[本文引用: 1]

ZHAO H X, CHI S Y, NING T Y, TIAN S Z, WANG B W, LI Z J. Covering farming pattern to improve soil physical properties and crop yield in wheat-maize cropping system
Transactions of the Chinese Society of Agricultural Engineering, 2013,29(9):113-122. (in Chinese)
[本文引用: 1]

[11] 许菁, 贺贞昆, 冯倩倩, 张亚运, 李晓莎, 许姣姣, 林祥, 韩惠芳, 宁堂原, 李增嘉. 耕作方式对冬小麦-夏玉米光合特性及周年产量形成的影响
植物营养与肥料学报, 2017,23(1):101-109.
[本文引用: 1]

XU J, HE Z K, FENG Q Q, ZHANG Y Y, LI X S, XU J J, LIN X, HAN H F, NING T Y, LI Z J. Effect of tillage method on photosynthetic characteristics and annual yield formation of winter wheat-summer maize cropping system
Journal of Plant Nutrition and Fertilizers, 2017,23(1):101-109. (in Chinese)
[本文引用: 1]

[12] 苏思慧, 王美佳, 张文可, 隋鹏祥, 王沣, 齐华. 耕作方式与玉米秸秆条带还田对土壤水稳性团聚体和有机碳分布的影响
土壤通报, 2018,49(4):841-847.
[本文引用: 2]

SU S H, WANG M J, ZHANG W K, SUI P X, WANG F, QI H. Effects of tillage practices and maize straw incorporation on water-stable aggregates and organic carbon in soils
Chinese Journal of Soil Science, 2018,49(4):841-847. (in Chinese)
[本文引用: 2]

[13] 代红翠, 张慧, 薛艳芳, 高英波, 钱欣, 赵海军, 成浩, 李宗新, 刘开昌. 不同耕作和秸秆还田下褐土真菌群落变化特征
中国农业科学, 2019,52(13):2280-2294.
[本文引用: 1]

DAI H C, ZHANG H, XUE Y F, GAO Y B, QIAN X, ZHAO H J, CHENG H, LI Z X, LIU K C. Response of fungal community and function to different tillage and straw returning methods
Scientia Agricultura Sinica, 2019,52(13):2280-2294. (in Chinese)
[本文引用: 1]

[14] ZHANG P, WEI T, JIA Z K, HAN Q F, REN X L, LI Y P. Effects of straw incorporation on soil organic matter and soil water-stable aggregates content in semiarid regions of northwest China
PLoS ONE, 2014,9(3):e92839.
URLPMID:24663096 [本文引用: 1]

[15] ZHANG P, CHEN X L, WEI T, YANG Z, JIA Z K, YANG B P, HAN Q F, REN X L. Effects of straw incorporation on the soil nutrient contents, enzyme activities, and crop yield in a semiarid region of China
Soil and Tillage Research, 2016,160:65-72.
[本文引用: 1]

[16] 殷文, 冯福学, 赵财, 于爱忠, 柴强, 胡发龙, 郭瑶. 小麦秸秆还田方式对轮作玉米干物质累积分配及产量的影响
作物学报, 2016,42(5):751-757.
[本文引用: 1]

YIN W, FENG F X, ZHAO C, YU A Z, CHAI Q, HU F L, GUO Y. Effects of wheat straw returning patterns on characteristics of dry matter accumulation, distribution and yield of rotation maize
Acta Agronomica Sinica, 2016,42(5):751-757. (in Chinese)
[本文引用: 1]

[17] 殷文, 柴强, 胡发龙, 樊志龙, 范虹, 于爱忠, 赵财. 干旱内陆灌区不同秸秆还田方式下春小麦田土壤水分利用特征
中国农业科学, 2019,52(7):1247-1259.
[本文引用: 1]

YIN W, CHAI Q, HU F L, FAN Z L, FAN H, YU A Z, ZHAO C. Characteristics of soil water utilization in spring wheat field with different straw retention approaches in dry inland irrigation areas
Scientia Agricultura Sinica, 2019,52(7):1247-1259. (in Chinese)
[本文引用: 1]

[18] 穆心愿, 赵霞, 谷利敏, 冀保毅, 丁勇, 张凤启, 张君, 齐建双, 马智艳, 夏来坤, 唐保军. 秸秆还田量对不同基因型夏玉米产量及干物质转运的影响
中国农业科学, 2020,53(1):29-41.
[本文引用: 1]

MU X Y, ZHAO X, GU L M, JI B Y, DING Y, ZHANG F Q, ZHANG J, QI J S, MA Z Y, XIA L K, TANG B J. Effects of straw returning amount on grain yield, dry matter accumulation and transfer in summer maize with different genotypes
Scientia Agricultura Sinica, 2020,53(1):29-41. (in Chinese)
[本文引用: 1]

[19] MU X Y, ZHAO Y L, LIU K, JI B Y, GUO H B, XUE Z W, LI C H. Responses of soil properties, root growth and crop yield to tillage and crop residue management in a wheat-maize cropping system on the North China Plain
European Journal of Agronomy, 2016,78:32-43.
[本文引用: 1]

[20] YOU D B, TIAN P, SUI P X, ZHANG W K, YANG B, QI H. Short-term effects of tillage and residue on spring maize yield through regulating root-shoot ratio in northeast China
Scientific Reports, 2017,7:13314.
URLPMID:29042601 [本文引用: 2]

[21] SUI P X, TIAN P, LIAN H L, WANG Z Y, MA Z Q, QI H, MEI N, SUN Y, WANG Y Y, SU Y H, MENG G X, JIANG Y. Straw incorporation management affects maize grain yield through regulating nitrogen uptake, water use efficiency, and root distribution
Agronomy, 2020,10(3):324.
DOI:10.3390/agronomy10030324URL [本文引用: 3]

[22] YANG H S, YANG B, DAI Y J, XU M M, KOIDE R T, WANG X H, LIU J, BIAN X M. Soil nitrogen retention is increased by ditch-buried straw return in a rice-wheat rotation system
European Journal of Agronomy, 2015,69:52-58.
[本文引用: 3]

[23] 安俊朋, 李从锋, 齐华, 隋鹏祥, 张文可, 田平, 有德宝, 梅楠, 邢静. 秸秆条带还田对东北春玉米产量、土壤水氮及根系分布的影响
作物学报, 2018,44(5):774-782.
[本文引用: 4]

AN J P, LI C F, QI H, SUI P X, ZHANG W K, TIAN P, YOU D B, MEI N, XING J. Effects of straw strip returning on spring maize yield, soil moisture, nitrogen contents and root distribution in northeast China
Acta Agronomica Sinica, 2018,44(5):774-782. (in Chinese)
[本文引用: 4]

[24] 张文可, 苏思慧, 隋鹏祥, 田平, 梅楠, 王沣, 王美佳, 张姣, 齐华. 秸秆还田模式对东北春玉米根系分布和水分利用效率的影响
生态学杂志, 2018,37(8):2300-2308.
[本文引用: 1]

ZHANG W K, SU S H, SUI P X, TIAN P, MEI N, WANG F, WANG M J, ZHANG J, QI H. Effects of straw incorporation modes on root distribution and water use efficiency of spring maize in northeast China
Chinese Journal of Ecology, 2018,37(8):2300-2308. (in Chinese)
[本文引用: 1]

[25] 鲍士旦. 土壤农化分析. 北京: 中国农业出版社, 2000: 34-35, 44-49, 56-58, 81, 106-107.
[本文引用: 2]

BAO S D. Soil and Agricultural Chemistry Analysis. Beijing: China Agriculture Press, 2000: 34-35, 44-49, 56-58, 81, 106-107. (in Chinese)
[本文引用: 2]

[26] KUCHENBUCH R O, GERKE H H, BUCZKO U. Spatial distribution of maize roots by complete 3D soil monolith sampling
Plant and Soil, 2009,315:297-314.
DOI:10.1007/s11104-008-9752-8URL [本文引用: 1]
The spatial distribution of root length density (RLD) is important for water and nutrient uptake by plants and biomass allocation in the soil. Experimental root assessment is, however, mostly based on methods that encompass only small fractions of the soil volume. The aim of this study was to characterize the three dimensional (3D) spatial distribution of RLD in the soil of a maize crop for plots of 37.5 and 75cm row spacing. At each plot, a 3D soil monolith of 70 × 40 × 30 (=84,000) cm³ was completely sampled in form of 84 cubic samples of 10cm edge length. Roots were washed from the soil and RLD was determined using the line intersect method. In 2004, mean RLD values were 0.41cm cm⁻³ for narrow and 0.34cm cm⁻³ for wide row spacing at row closure (55days after planting; DAP) and 0.74cm cm⁻³ (1.37cm cm⁻³ in 2003) for narrow and 0.77cm cm⁻³ (0.96cm cm⁻³ in 2003) for wide row spacing at tasseling (104 DAP). The CV values for RLD of 48% to 72% in 2004 were first higher for wide than for narrow row spacing but at the later growth stage (tasseling) lower for wide than for narrow. For individual vertical soil slices, CV values for RLD were about 40–60%, irrespective of the orientation of the slice. The results suggest that RLD was related mainly to the spatial location and the plant row structure, and not governed unambiguously by SBD or SWC. The spatially distributed maize root data suggest that variability of RLD parallel to plant rows is not negligible. Any simplified use of 1D or 2D vertical samples at separate locations may lead to erroneous estimations of RLD profiles.

[27] KASHIWAGI J, KRISHNAMURTHY L, PURUSHOTHAMAN R, UPADHYAYA H D, GAUR P M, GOWDA C L L, ITO O, VARSHNEY R K. Scope for improvement of yield under drought through the root traits in chickpea (Cicer arietinum L.)
Field Crops Research, 2015,170:47-54.
[本文引用: 1]

[28] CAI H G, MA W, ZHANG X Z, PING Z Q, YAN X G, LIU J Z, YUAN J C, WANG L C, REN J. Effect of subsoil tillage depth on nutrient accumulation, root distribution, and grain yield in spring maize
The Crop Journal, 2014,2(5):297-307.
DOI:10.1016/j.cj.2014.04.006URL [本文引用: 1]

[29] REN B Z, LI X, DONG S T, LIU P, ZHAN B, ZHANG J W. Soil physical properties and maize root growth under different tillage systems in the North China Plain
The Crop Journal, 2018,6:669-676.
DOI:10.1016/j.cj.2018.05.009URL [本文引用: 2]

[30] XU X, PANG D W, CHEN J, LUO Y L, ZHENG M J, YIN Y P, LI Y X, LI Y, WANG Z L. Straw return accompany with low nitrogen moderately promoted deep root
Field Crops Research, 2018,221:71-80.
[本文引用: 1]

[31] BURTON A L, LYNCH J P, BROWN K M. Spatial distribution and phenotypic variation in root cortical aerenchyma of maize (Zea mays L.)
Plant and Soil, 2013,367:263-274.
DOI:10.1007/s11104-012-1453-7URL [本文引用: 1]
Previous research has suggested that root cortical aerenchyma (RCA) can enhance soil exploration and crop performance by decreasing root respiration. This trait is a potential breeding target for adaptation to abiotic stresses such as drought and low nutrient availability. However, little is known of phenotypic variation in aerenchyma or its distribution among root classes.
The spatial distribution of RCA was evaluated in freehand sections from 13 sites in the root systems of 11 recombinant inbred and commercial lines of maize (Zea mays). RCA variation was evaluated in 583 recombinant inbred lines of maize at one sampling position.
RCA varied significantly among root classes and axial positions. Genotypic differences were observed for the amount of RCA at corresponding sampling locations and for the mean amount of RCA across all sampling locations, but genotypes did not differ in the proportional distribution of RCA within the whole root system. The amount of RCA in a cross-section was independent of several other anatomical traits.
There is substantial genetic variation for RCA, and this variation is independent of other anatomical traits. RCA can be phenotyped in greenhouse-grown plants by sampling the middle parts of second- or third-whorl crown roots.

[32] BIAN D H, JIA G P, CAI L J, MA Z Y, ENEJI A E, CUI Y H. Effects of tillage practices on root characteristics and root lodging resistance of maize
Field Crops Research, 2016,185:89-96.
DOI:10.1016/j.fcr.2015.10.008URL [本文引用: 1]

[33] 王沣, 王美佳, 苏思慧, 王英俨, 苏业涵, 孟广鑫, 孙悦, 齐华, 姜英. 水分胁迫下秸秆还田对玉米产量和根系空间分布的影响
应用生态学报, 2018,29(11):3643-3648.
DOI:10.13287/j.1001-9332.201811.023URLPMID:30460811 [本文引用: 2]
To investigate the effects of straw amendments on the yield and root spatial distribution of maize under water stress, an experiment with rainproof shelter was conducted in the field experimental station of Shenyang Agricultural University in 2016 and 2017. The drip irrigation facilities were used to perform water stress treatments. Straw burying (T1) and straw incorporation (T2) as two approaches of straw amendments were conducted combined with three depths of 15 cm (D1), 30 cm (D2), and 45 cm (D3) for straw returning, ploughing tillage at above three depths without straw presence as control in this study. During seedling and silking stages of maize, drought and water logging stresses were introduced respectively to the plants. Our results showed that the yield of maize under S1T1D2 treatment in 2016 was significantly increased by 5.7%-7.1%. Compared with all the rest treatments, the dry weights of lateral roots and deep roots under S1T1D2 treatment were increased by 67.3%-149.9% and 17.9%-116.4%, respectively. The dry matter accumulation in shoot of maize observed from S1T1D2 treatment was significantly lower than those under other treatments, with 2.1%-35.8% reduction. Our results indicated that S1T1D2 could significantly promote the growth and spatial distribution of maize root, accounting to release water stress and keep yield stabilization or promotion. Therefore, 30 cm of straw burying could be used as a suitable approach of straw returning for maize production in northeastern China, where the climate is with a pattern of drought first and waterlogging in later stage.
WANG F, WANG M J, SU S H, WANG Y Y, SU Y H, MENG G X, SUN Y, QI H, JIANG Y. Effects of straw returning on maize yield and root system spatial distribution under water stress
Chinese Journal of Applied Ecology, 2018,29(11):3643-3648. (in Chinese)
DOI:10.13287/j.1001-9332.201811.023URLPMID:30460811 [本文引用: 2]
To investigate the effects of straw amendments on the yield and root spatial distribution of maize under water stress, an experiment with rainproof shelter was conducted in the field experimental station of Shenyang Agricultural University in 2016 and 2017. The drip irrigation facilities were used to perform water stress treatments. Straw burying (T1) and straw incorporation (T2) as two approaches of straw amendments were conducted combined with three depths of 15 cm (D1), 30 cm (D2), and 45 cm (D3) for straw returning, ploughing tillage at above three depths without straw presence as control in this study. During seedling and silking stages of maize, drought and water logging stresses were introduced respectively to the plants. Our results showed that the yield of maize under S1T1D2 treatment in 2016 was significantly increased by 5.7%-7.1%. Compared with all the rest treatments, the dry weights of lateral roots and deep roots under S1T1D2 treatment were increased by 67.3%-149.9% and 17.9%-116.4%, respectively. The dry matter accumulation in shoot of maize observed from S1T1D2 treatment was significantly lower than those under other treatments, with 2.1%-35.8% reduction. Our results indicated that S1T1D2 could significantly promote the growth and spatial distribution of maize root, accounting to release water stress and keep yield stabilization or promotion. Therefore, 30 cm of straw burying could be used as a suitable approach of straw returning for maize production in northeastern China, where the climate is with a pattern of drought first and waterlogging in later stage.

[34] TIAN P, SUI P X, LIAN H L, WANG Z Y, MENG G X, SUN Y, WANG Y Y, SU Y H, MA Z Q, QI H, JIANG Y. Maize straw returning approaches affected straw decomposition and soil carbon and nitrogen storage in northeast China
Agronomy, 2019,9:818.
DOI:10.3390/agronomy9120818URL [本文引用: 1]

[35] DORDAS C. Variation in dry matter and nitrogen accumulation and remobilization in barley as affected by fertilization, cultivar, and source-sink relations
European Journal of Agronomy, 2012,37:31-42.
DOI:10.1016/j.eja.2011.10.002URL [本文引用: 1]
Barley (Hordeum vulgare L.) is one of the most important cereals worldwide and is being increasingly grown in many areas of the world, but there is a lack of information about the physiological processes limiting grain yield. A two-year field study was conducted with the objective of determining the effect of different rates of nitrogen (N) (control, 60 kg N ha(-1), and 120 kg N ha(-1)) on source-sink relations, dry matter and N remobilization, and grain yield. Therefore, the source-sink ratio was manipulated to examine the factor(s) limiting grain filling under rainfed conditions. The treatments were: I, control; II, half of the spike was removed; Ill, the entire spike was removed. The distribution of dry matter, N among grains, and culms and leaves were analyzed at anthesis and harvest. Dry matter accumulation and partitioning into different plant parts were affected by the fertilization treatments and increased as the N level increased. At anthesis, the amount of leaf+ culm dry matter was greater than the amount of spike dry matter. N fertilization slightly affected the N concentration of the different plant parts at anthesis and at maturity. N content was affected by the fertilization treatments and was increased by 62% over the two years of the study compared with the control. In addition, dry matter remobilization was an average of 40% higher in the fertilized treatments compared with the control, which indicates that fertilization led plants to translocate higher amounts of dry matter. N remobilization was affected by the fertilization treatment and by the sink reduction. The spike reduction treatment increased the pre-anthesis assimilates and contribution to grain, indicating that the dry matter remobilization from vegetative tissues were very important for grain development. In contrast, N translocation efficiency was similar under sink reduction. Grain yield was determined by biomass and harvest index, and at the half spikes, there was a higher contribution at the harvest index. In addition, grain N yield was determined more by grain yield and less by the N concentration. The present study indicates that N fertilization and sink size can affect dry matter and N accumulation, partitioning, and remobilization in barley, which can affect grain yield. (C) 2011 Elsevier B.V.