Effects Of Soil Moisture And Root Excision On Water And Nutrition Consumption And Physiology Of Winter Wheat

In order to study the regulation effects and influence mechanisms of winter wheat growth,physiology and water consumption under different soil water conditions and plant roots incertain soil depth. We used the research device named glass soil pillar for root investigation,chose Changhan58as the material, to accurately control the soil relative water content as50%(W1);70%(W2);90%(W3). The effects of root excision on photosynthetic characteristics,yield, root length, canopy temperature, water consumption and soil nutrient of winter wheat injointing stage were studied. Main research conclusions were obtained as below:1. The transpiration and stomatal conductance(Gs) decreased significantly in differentwater conditions during booting stage~flowering stage when treated by root excision at50cm,transpiration rate (Tr) decreased by20.3%~10.3%. The highest reduction rate of Tr can beobtained in W2water condition, Gs was easier to be reduced by root excision in higher watercondition (W3). Root excision had no effects on Tr and Gs of filling stage, Tr and Gsincreased with soil water content in this period. The photosynthetic rate(Pn) increased by5.5%~7.6%treated by root excision in different water conditions only during filling stage, butthe effects of different water conditions on Pn showed no significant difference. Root excisionraised the water use effeciency(WUEL) of flag leaf during booting~flowering stage. Comparedto constantly root treatment, WUELincreased by18.1%~10.2%(W1),5.1%~11.4%(W2),6.2%~7.0%(W3) respectively; Till the filling stage, WUELincreased7.0%(W1),9.5%(W2),4.8%(W3) respectively. The effects of root excision on Fv/Fm and Fv/Fo showed nosignificant difference; Root excision raised the ETR of W1and W2under the filling stagesignificantly; During the booting stage, ΦPSⅡ in W3water condition was decreasedsignificantly.2. Root excision treatment in W1and W2significantly decreased the leaf area(LA)during booting~filling stage, showed no significant effect on LA in W3;Plant height was reduced(P<0.05)in partial treatments during booting and heading stage;No significant effect of root excision on stem diameter. In the condition of W1, W2, W3, rootexcision increased the thousand grain weight to5.2%,3.6%,5.5%respectively. The grainnumber per spikes decreased8.5%(W1) and7.2%(W2)(P<0.05). The spikes number decreased by13.7%(P<0.05) in W1. The yield decreased by18.1%and9.1%(P<0.05) in W1and W2respectively, increased by4.4%in W3.3. Root excision can reduce the root length, the length of surface roots (50~260cm indepth) were reduced by27.9%,20.6%,2.0%in W1, W2, W3respectively during headingstage; They were decreased by20.2%,22.4%,1.2%in W1, W2, W3respectively duringfilling stage.4. Root excision can improve the canopy temperature (12:00) of W1and W2in bootingstage, and that (12:00) of W2in heading stage respectively; but the effect of root excision oncanopy temperature showed no apparent differences in flowering and filling stage. In thefilling stage, canopy temperature of winter wheat decreased significantly with the increasingof soil moisture (P<0.05).5. At the same growth period, the water consumption of winter wheat was increased withincreasing of soil moisture, and showed significant differences in W1, W2and W3(P<0.05).Root excision significantly reduced the water consumption of winter wheat in booting stageas W1(5.1%), W2(5.3%), W3(4.1%) respectively. The effect of root excision on soil nutrientconsumption showed no significant difference.