| In order to understand water consumption patterns and water use efficiency of winter wheat under subsurface irrigation,the study was designed five treatments（T1: no spring irrigation,T2:conventional irrigation at jointing stage,T3:subsurface irrigation at jointing stage,T4:subsurface irrigation at jointing and flowering stage,T5:conventional irrigation at jointing and flowering stage）. Evapotranspiration,soil moisture dynamic and water use efficiency of these treatments were studied by weighing lysimeters. The results showed that water consumption characteristic of winter wheat was bimodal curve over the whole growth stage; evapotranspiration peak appeared in fifth day of subsurface jointing irrigation,while in third day of conventional jointing irrigation. The daily evapotranspiration characteristic was “single peak curve” under subsurface and conventional irrigation; the treatment of subsurface jointing irrigation appeared “negative luxury water consumption” in the early jointing stage,and much more water was used from late jointing stage to filling stage,then,subsurface flowering irrigation decreased water consumption,thus,the total water use of subsurface irrigation treatment was lower 1.33%-4.77% than conventional.Subsurface irrigation mainly increased soil moisture of 60 cm to 100 cm,while conventional irrigation increased soil moisture of 0-40 cm. Subsurface irrigation increased spike grain number,thousand seed weight,water use efficiency,harvest index,and reduced the biomass,grain nitrogen accumulation amount. Generally,subsurface irrigation changed the water consumption model by affecting soil moisture of layers,namely,saving water was used for late growth stage by restraining soil evaporation; increased water use efficiency and harvest index,reduced grain quality. |
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