摘要
为探究干旱胁迫条件下淮北平原夏玉米生长期水分利用特征,分析农田降水-土壤水-作物水之间的转化规律。通过野外实验和室内分析,测定分析不同生长期内降水、土壤水、植物水、地下水的稳定氢氧同位素值。采用稳定氢氧同位素技术分析了各水体的同位素分布特征,利用直接对比法和多元线性混合模型法分析夏玉米对土壤水分的主要吸水深度及贡献率,进而研究其水分来源。结果表明,五道沟实验站夏季大气降水线方程为δD=7.26×δ^(18)O+3.11(R^(2)=0.98),其斜率和截距均小于全球大气降水线方程,表明降水在降落过程存在蒸发富集过程。土壤水氢氧同位素在垂直方向剖面呈现明显的梯度分布。干旱胁迫条件下,夏玉米拔节-抽雄期主要吸收0~20、20~40、40~60 cm处的土壤水,贡献率分别为21.8±13.6%、25.5±20%和25.1±18.2%;抽雄-灌浆期主要吸收0~20 cm处的土壤水,贡献率为68.6±3.6%;灌浆-成熟期主要吸收0~20 cm处的土壤水,贡献率为72.0±0.9%。夏玉米根系优先利用浅层土壤水,土壤水主要来自大气降水。地下水埋深较浅地区,干旱条件下夏玉米在整个生长期内根系吸水深度较浅,由此考虑生长期改变灌溉方式来提高灌溉水利用率。
In order to investigate the characteristics of water use during the growing period of summer maize in the Huaibei Plain under drought stress conditions,and to analyse the field water movement and transference laws in the precipitation-soil-crop continuum.Stable hydrogen and oxygen isotope values of precipitation,soil water,plant water,and groundwater were determined and analysed during different growing periods by field experiments and indoor analyses.Stable hydrogen and oxygen isotope techniques were employed to examine the isotopic distribution characteristics of the water bodies,and direct comparison and multivariate linear regression methods were used to analyse the sources of summer maize root water uptake and their contributions.The local meteoric water line at the Wudaogou Experimental Station wasδD=7.26×δ^(18)O+3.11(R^(2)=0.98),with a slope and intercept smaller than those of the global meteoric water line.This indicates that there was an evapotranspiration-enrichment process of precipitation in the landing process.Soil water hydroxide isotopes showed a clear gradient distribution in the vertical profile.Under drought stress conditions,summer maize primarily absorbed soil water at depths of 0~20,20~40 and 40~60 cm during jointing-tasseling stage,with the contribution rates of 21.8±13.6%,25.5±20%and 25.1±18.2%,respectively.The soil water at 0~20 cm was mainly absorbed during tasseling-filling stage,and the contribution rate was 68.6±3.6%.The soil water at 0~20 cm was mainly absorbed in the filling-maturity stage,and the contribution rate was 72.0±0.9%.Summer maize roots preferentially use shallow soil water,which mainly derived from atmospheric precipitation.In the area with shallow groundwater depth,the root water absorption depth of summer maize remains shallow throughout the whole growth period under drought conditions.Therefore,it is considered to change the irrigation method during the growth period to enhance the utilization rate of irrigation water.
作者
董国强
胡勇
陈小凤
司巧灵
王敏杰
阮宏威
DONG Guo-qiang;HU Yong;CHEN Xiao-feng;SI Qiao-ling;WANG Min-jie;RUAN Hong-wei(Anhui and Huaihe River Institute of Hydraulic Research,Hefei 230088,China;Key Laboratory of Water Conservancy and Water Resources of Anhui Province,Bengbu 233000,Anhui Province,China)
出处
《节水灌溉》
北大核心
2024年第4期114-119,共6页
Water Saving Irrigation
基金
国家自然科学基金项目(52109048,51809002)
安徽省自然科学基金水科学联合基金(2208085US16)
安徽省·水利部淮河水利委员会水利科学研究院青年科技创新基金项目(KY202103,KY202207)
安徽省引江济淮集团有限公司科技项目(YJJH-ZT-ZX-20230706545)
水利部重大科技项目(SKS-2022066)。
关键词
夏玉米
干旱胁迫
土壤水
氢氧同位素
根系水分来源
summer maize
drought stress
soil water
hydrogen and oxygen isotopes
water source of root system
