The Influence Of Different Water Supplied On Root Morphology And Water Uptake Ability In Winter Wheat

Root is an important organ of winter wheat to absorb soil water.The growth and distribution of root system directly related to the formation of drought resistance and yield of winter wheat.In this paper,the plan wetting layer was closely related to the root distribution depth of winter wheat.PVC pipe buried soil column method was applied to the winter wheat experiment in Water Saving Irrigation Technology Training Field and Demonstration Garden of Shanxi Conservancy Technical College during October 2014 to June 2015 and October 2015 to June 2016.5 different irrigation depth(?treatment as surface irrigation,treatment ?to ? as root distribution depth of 40%,60%,75% and 90%)was set through change of irrigation method.Effects of deep irrigation and surface irrigation on root growth and water uptake of winter wheat was analyzed.The effects of deep irrigation and surface irrigation on root growth and water uptake of winter wheat were analyzed to seek a reasonable water control plan for winter wheat in order to provide theoretical basis for reasonable irrigation of winter wheat and active drought resistance changing from passive in the arid and semi arid area of China.Research result is following:(1)Under different irrigation depth,the soil moisture dynamic change of 0-300 cm in the root zone of winter wheat was obvious.The soil profile moisture of winter wheat increased at first and then decreased and then increased with the increase of soil depth.The surface soil water content of the surface irrigation was higher than that of the deep irrigation treatment.But below the surface,the situation is opposite.The greater the depth of irrigation,the higher the depth of soil profile.The maximum value was existed when the depth of irrigation was 90% of the depth of root distribution.(2)Under different irrigation depth,When the soil depth is shallower(Depth of soil <150cm),the soil temperature of surface irrigation treatment was significantly lower than that of the other four irrigation treatments.When the irrigation depth was 90% of the root distribution depth,the soil temperature was the maximum.This shows that the change of irrigation depth can increase the soil temperature to a certain extent,and play a positive role in the growth of the crop.During the whole growth period,the temperature of soil profile decreased first and then increased slowly with the increase of soil depth in the jointing stage.At heading stage,filling stage and maturity stage,the soil temperature showed a decreasing trend with the increase of soil depth.(3)With the increase of irrigation depth,the depth of the root of winter wheat increased,the total root length and total dry weight increased in different degrees.The total root length and total dry weight of each treatment reached the maximum at heading stage or filling stage,and decreased at maturity.The effect of different irrigation depth on root length and root weight was the largest before heading stage.In the late growth stage of winter wheat,the root growth of the irrigation depth is not better,irrigation depth of 90% of the depth of the root distribution will have a negative effect on the growth of the root,making the total root length and total root weight reduction.Based on the variation of the root length density of Winter Wheat with soil depth and the growth period,the vertical distribution function and the two factor fitting function of the root length density were established.(4)Compared with the ground water irrigation,the deep irrigation mode changed the spatial distribution of root activity,and significantly increased the root activity of the soil profile.The proper depth of irrigation is helpful to delay the aging process of Winter Wheat in late growth period,slow down the upper root vigor decreased speed,the winter wheat root system to maintain the overall larger root activity value,and to the depth of irrigation root distribution depth of 75% is the best.(5)Based on the hydrogen and oxygen stable isotope technology,the depth of root water uptake of Winter Wheat in the whole growth period was mainly focused on 0-40 cm.However,during the period of heading and filling stage,the dependence of winter wheat on deep soil water is deeper,and the supply of deep soil moisture is very important to the growth and development of winter wheat.But the effects of different irrigation treatments on root water uptake of winter wheat were mainly reflected in the improvement of deep soil water uptake and utilization,especially the irrigation depth of 75% and 90% treatment of root depth.The depth of root water uptake of winter wheat was significantly influenced by the heading and grain filling stage.By means of correlation analysis and path analysis,it showed that there was a significant correlation between root water uptake and root growth and soil water status.But lower determination coefficients reveal the importance of stable isotope techniques in the study of the characteristics of root water uptake.(6)The harvest index of winter wheat was significantly increased under deep irrigation.The higher the irrigation depth,the higher the harvest index.Compared with surface irrigation,deep irrigation mainly by increasing the number of ears in single pillar,single grain number and the weight of 1000 ears increased yield.In different years,the irrigation depth of the root distribution depth of 75% reached the maximum yield of 8492.76kg/hm2,compared with surface irrigation increased by 29.9%.(7)Deep irrigation increased the yield by increasing the water consumption of winter wheat at the jointing stage to the mature stage.The total water consumption of the deep irrigation treatment was less than that of the surface irrigation,and the irrigation depth was the maximum of 75% treatments.Deep irrigation increased rainfall and irrigation water consumption,reduced the consumption of soil water storage,and increased the water use efficiency.Through the analysis of 2 years,the water use efficiency of winter wheat with treatment IV was higher.(8)Comprehensive analysis of Winter Wheat under different irrigation depth distribution of soil moisture content,soil temperature,root growth,water uptake,yield and water use efficiency,can draw the irrigation depth of 75% root depth distribution is the optimal irrigation depth obtained under the experimental conditions.