摘要
干旱限制作物生长发育和产量形成,要科学解除干旱,需明确作物受旱开始时间和对干旱的响应机制。本文以春玉米“科河28号”为材料,设置正常灌溉和持续干旱两种处理,探求干旱区大旱年干旱发生发展过程中春玉米生长受限和干旱胁迫的早信号、显著影响期及土壤水分阈值。结果表明:(1)捕捉大旱年干旱对田间指标影响的早信号,试验处理21 d叶片含水率开始减小,试验处理28 d影响株高和叶面积增长,试验处理32 d影响叶片干物质积累。(2)解除持续干旱产生不可逆影响的时间,株高、叶面积、各器官干物质积累和含水率分别在试验处理49、56、63 d和70 d;最小土壤贮水量为74.6、69.0、58.0 mm和56.5 mm,最大土壤水分亏缺量为30.4、37.8、47.2 mm和43.6 mm。(3)持续干旱对春玉米干物质积累和含水率的影响,叶片>叶鞘>茎>穗,且持续干旱造成经济产出小。(4)持续干旱对田间指标的影响效果为:拔节期显著,抽雄期最大,乳熟期出现负增长。(5)持续干旱对产量构成的影响:与正常灌溉相比,果穗长减小70%,果穗粗减小45%,秃尖长增大33%,百粒重减小73%,株子粒重减小84%,理论产量减小85%。(6)干旱持续21 d是春玉米受旱早信号,49 d是影响不可逆期。春玉米三叶~七叶期和灌浆后期少灌水或不灌水对产量影响较小,拔节水、抽雄水是保障产出的关键水。
Drought restricts crop growth and yield formation.To scientifically relieve drought,it is necessary to make clear about the beginning time and response mechanism to the drought.This paper took the spring maize Kehe 28 as the material and the two treatments of normal irrigation and continuous drought were set up during the whole growth stage.The changes of spring maize,the early signals of drought stress,the period of significant influence,and the threshold of soil moisture were explored during drought occurrence and development in the arid area.The results showed that:(1)To capture the early signals of the drought effects on field indicators during drought years,water content of leaves started to decrease in 21 d after experimental treatment,plant height and leaf area growth were affected by 28 d after experimental treatment,and dry matter accumulation of leaves was affected by 32 d after the treatment.(2)In the initial period when the significant effects of continuous drought were lifted,plant height,leaf area per plant,dry matter accumulation,and water content of each organ were 49,56,63 d,and 70 d after experimental treatment,respectively.The minimum soil water storage were 74.6,69.0,58.0 mm,and 56.5 mm,and the maximum soil water deficits were 30.4,37.8,47.2 mm,and 43.6 mm,respectively.(3)The effects of continuous drought on dry matter accumulation and moisture content of spring maize were:leaves>sheaths>stems>ears,and the continued drought caused a small economic output.(4)The effects of continuous drought on field indicators were significant at the jointing stage,the tasseling stage was the largest,and the milk ripening stage had a negative increase.(5)The effects of continuous drought on the yield composition:compared with normal irrigation,the ear length decreased by 70%,ear diameter decreased by 45%,bare tip length increased by 33%,seed weight decreased by 73%,seed weight decreased by 84%,and theoretical yield decreased by 85%.(6)The drought duration of 21 d was the early signal of drought in spring maize
作者
蒋菊芳
王润元
张凯
杨华
魏育国
JIANG Jufang;WANG Runyuan;ZHANG Kai;YANG Hua;WEI Yuguo(Wuwei Meteorological Bureau of Gansu Province, Wuwei, Gansu 733000, China;Institute of Arid Meteorology of China Meteorological Administration, Key Laboratory of Arid Climatic Change and ReducingDisaster of Gansu Province, Key Laboratory of Arid Change and Disaster Reducing of CMA, Lanzhou, Gansu 730020, China)
出处
《干旱地区农业研究》
CSCD
北大核心
2020年第6期226-233,共8页
Agricultural Research in the Arid Areas
基金
国家自然基金(41275118,2012CB955304)
公益性行业(气象)科研专项(重大专项)(GYHY201506001-2)
甘肃省气象局十人计划(GSMArc2019-03)
干旱基金(IAM202015)
武威市科技计划项目(WW180213)。
关键词
持续干旱
春玉米
生长指标
土壤贮水量
土壤水分亏缺量
continuous drought
spring maize
growth indicators
soil water storage
soil water deficit
