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用圆柱状管栽实验研究了上层供水和下层供水对春小麦根源信号和水分利用效率的影响． 供试春小麦品种为陇春８１３９ － ２ 和高原６０２ ． 处理方式为： １） 整个管体内土壤含水量保持在８０ ％ ～９０ ％ 田间持水量（ＦＷＣ） （ＩＦ） ； ２） 土壤表面以下１０ｃｍ 处浇水使管内整体土壤含水量保持在５０ ～６０ ％ ＦＷＣ （ＩＴ） ； ３） 在管体长７／１０ 处浇水使管内整体土壤含水量保持在５０ ～６０ ％ ＦＷＣ （ＩＢ）． 相对于ＩＦ 和ＩＴ 处理， 苗期到分蘖期ＩＢ处理叶气孔导度显著下降， 但叶水势基本不变， 表明有明显的非水力根信号现象． 在拔节期及以后， ＩＢ 处理土壤上层根生物量比例下降， 中层根生物量增加， 非水力根信号消失． ＩＢ 处理的水分利用效率显著高于其它处理， 这意味着播种前通过水量较多的灌溉增加深层土壤水分将有利于提高水分利用效率．
The effects of upper water supply and lower water supply on the root signal and water use efficiency of spring wheat were studied with cylindrical tube plantations. The spring wheat varieties tested were Longchun 8139-2 and plateau 602. The treatment methods are as follows: 1) The soil water content of the whole pipe body is kept at 80% -90% of the field capacity (FWC); 2) Water content of 10cm below the soil surface keeps the overall soil water content in the pipe at 50-60% FWC (IT); 3) Watering at 7/10 tube length maintains overall soil water content in the tube at 50-60% FWC (IB). Compared with IF and IT treatments, leaf stomatal conductance decreased significantly at seedling stage to tillering stage, but leaf water potential remained almost unchanged, indicating obvious non-hydraulic root signal phenomenon. At the jointing stage and later, the proportion of root biomass in the top layer of IB decreased, the middle root biomass increased, and the non-hydraulic root disappeared. The water use efficiency of IB treatment was significantly higher than that of other treatments, which means that increasing deep soil moisture through irrigation with more water before sowing would be beneficial to improve water use efficiency.