交替沟灌条件下土壤水稳定氢氧同位素分布特征  

Characteristics of Stable Hydrogen and Oxygen Isotopes in Soil Water under Alternate Partial Root-zone Furrow Irrigation

作　　者：吴友杰 魏镇华[1] 杜太生[1] 

机构地区：[1]中国农业大学中国农业水问题研究中心,北京100083

出　　处：《灌溉排水学报》2014年第4期251-255,共5页Journal of Irrigation and Drainage

基　　金：国家自然科学基金项目(51222905);国家863计划课题(2011AA100505);水利部公益项目(201201003);教育部"新世纪优秀人才支持计划"项目(NCET-11-0479)

摘　　要：为深入探讨根系分区交替灌溉的节水机理，分析了交替沟灌务件下土壤水稳定氢氧同住素分布特征及不同层次土壤水对玉米根系吸水的贡献率，明确了玉米根系吸水来源。结果表明，土壤水稳定氢氧同位素在沟、垄表层富集，沟中是垄上的28．78％。灌溉和降雨后，沟中表层土壤水稳定氢氧同位素分布发生突变，垄上变化较小。交替沟灌下灌水沟、非灌水沟和垄的不同深度土壤水对玉米根系吸水的贡献存在显著差异；玉米拔节期根系吸水主要来源于垄下10-20cm土层，贡献率为88％-97％；抽穗期来源于垄下20-40cm土层，贡献率为58％-92％，灌溉后主要供水层是灌水沟下O-10cm和垄下20-40cm土层。交替沟灌下采用小定额灌溉和不同生育期采用适宜的计划湿润层设计灌溉制度是提高作物水分利用效率的关键。In order to further clarify the water-saving mechanism of alternate furrow irrigation, the distributions of δD and δ^18O in soil water and the contribution of soil water to root water uptake in different soil layers were analyzed under alternate furrow irrigation, and the source of root water uptake was made clear. The results showed that： enrichment of hydrogen and oxygen stable isotopes in soil water appeared in soil surface layer, and the enrichment of furrow was 28.78% of the ridge. After irrigation and rainfall, a mutation of δD and δ^18O in soil water appeared in furrow surface layer, but δD and δ^18 O in soil water changed slightly on the ridge. The contributes of soil water in different soil profiles to maize root water uptake were significantly different in the dry furrow, the wet furrow and ridge under alternate partial rootzone furrow irrigation. The source of maize root water uptake was mainly from 10-20 cm layer with the contribution rate of 88%-97% in jointing stage while it was from 20-40 cm layer with contribution rate of 58%-92% in heading stage, and it was from 0-10 cm layer of wet furrow and 20-40 cm layer of ridge after irrigation. Low irrigation quota and the appropriate plan wetting layer are the key to improve crop water use efficiency under alternate furrow irrigation.

关 键 词：交替沟灌 稳定氢氧同位素 土壤水分 玉米 根系吸水 

分 类 号：S275.3[农业科学—农业水土工程]