Study on the Root Distribution and Root Characteristics of Winter Wheat under Different Soil and Water Conditions

[Objective]To investigate root distribution and root-canopy characteristics of winter wheat varieties under different soil water conditions,provide the necessary theoretical basis for the scientific irrigation. [Method]Pond culture method was adopted,4 treatments( excessive irrigation,moderate irrigation,slight drought and severe drought) applied. Quantifying irrigation was used in different growth stages of winter wheat varieties,roots of these wheat varieties taken from different soil layers( 0- 10 cm,10- 20 cm,20- 30 cm),dry weight of aboveground parts measured,root-canopy ratio calculated. [Result]Root distribution and root-canopy ratio of 2 winter wheat varieties under 4water gradients were different from each other,dry weight of roots in 0- 10 cm soil layer accounts for 80% and higher,that in 10- 20 cm soil layer 10%,that in 20- 30 cm soil layer 5%. Under slight drought,root-canopy ratio of big-ear wheat variety Shannong 21 increases,that of small-ear wheat variety Shannong 20 also increases in all growth stages except the maturation stage. [Conclusion]The demand of rainfall was about more than 460 mm in the whole growth period of wheat in North China,however,the average annual rainfall was only about 150 mm.The study showed that through reducing the number of irrigation appropriate,wheat yield didn't necessarily fall.