Research On Growth And Soil Hydrothermal Change Of Winter Wheat Under Different Irrigation Depths

According to the test of winter wheat average maximum root depth,combined with the field water holding rate of artificial regulation of water in winter wheat root zone,to promote the growth of root system so as to promote the accumulation of above ground biomass and distribution,water saving irrigation,increased winter wheat yield to.Test using plastic pipe soil column in Shanxi Conservancy Technical College training base,studied five irrigation depth: surface irrigation(T1)irrigation,root distribution depth is 40%(T2),depth of root distribution of 60% irrigation(T3)irrigation,root distribution depth is 75%(T4),water depth root distribution of 90%(T5)under the condition of root root zone water heat pattern,growth of winter wheat,plant height,leaf area index,root growth,photosynthesis,water use efficiency and yield.The principal component analysis was used to analyze the physiological indexes of the plant growth period,and the best irrigation depth was obtained.Main results:(1)The depth of different irrigation treatments,the soil moisture of soil in root zone of 0-300 cm in each period showed increased first and then decreased,then increased and then decreased,with the depth increase slowly in fluctuation of the " double-peak " trend,the bottom to maintain a high water content,the bottom of the water content of surface soil can reach 2 times.Large fluctuations in soil moisture appeared after irrigation or rainfall that irrigation has a significant impact on soil moisture,root zone of winter wheat water fitting function changes with depth exponentially increasing trend,and in accordance with the exponential increase equation.(2)Because of the influence of each period under different irrigation depth,the soil temperature also showed increased with the irrigation depth increasing in the temperature difference between different soil layers,and in the 0-150 cm winter wheat root zone soil,T1 soil temperature is significantly lower than the other four treatments,T5 treatment soil temperature,winter wheat root zone temperature fitting function change with depth is logarithmic decreasing,and logarithmic decline equation,y=-A(x)+b.(3)Compared to surface irrigation treatment T1,the maximum root depth to the mature period of T2,T3,T4,T5 deep respectively than T1 long 20 cm,40cm,60 cm,62cm,deep and effective irrigation induced root absorption of water,promoted the root deep,irrigation treatment T3,deep T4 the most conducive to the total root length becomes larger,the deepest depth is not the most conducive to the total root length becomes large,shallow depth is not the best treatment.The irrigation depth in the early growth stage to promote root growth and the root senescence relative to other advanced treatment too quickly at later growth stage,resulting in dead root roots,total root dry weight decreased more.(4)The general trend root activity is from winter began to increase,reached the maximum in the jointing stage and then decreased,T1 was significantly lower than other treatments at jointing,heading,T5>T4>T3>T2>T1,shows that during this period,the greater the depth of irrigation root activity was higher,the grouting mature T4>T3>T5> T2>T1,deep irrigation is beneficial to increase the root vigor and T3 and T4 significantly increased the overall value of winter wheat root activity,but in the late growth stage of plant,irrigation depth is too large but not the most conducive to root vigor.(5)Deep T2,T3,T4 water,T5 processing plant height,above ground biomass than surface irrigation treatment T1 deep irrigation is beneficial to promote plant photosynthesis,leaf water T3,under T4 treatment is conducive to efficiency greatly,that is the depth distribution of root irrigation depth 60%,75% at the most conducive to the use of the leaves water(6)In different depths,the yield was increased by increasing the length of ear,the number of grains per ear,the number of spikes and the total biomass of the column.T3(irrigation depth is 60% of root distribution depth),T4(irrigation depth of root distribution depth of the treatment of 75%)showed its advantages,is conducive to the increase of yield,yield structure improvement.(7)Through principal component analysis,considering the various indicators under the condition of irrigation depth of root distribution depth of 75%T4 treatment is most beneficial to the plant,is the most suitable depth of winter wheat growth under the conditions of deep irrigation.