不同灌水量对滴灌春小麦根系时空分布、水分利用率及产量的影响
Effects of Drip Irrigation Amount on Root Spatial and Temporal Distribution, Water Use Efficiency and Yield in Spring Wheat

Field experiment was conducted to explore the spatial and temporal distribution of wheat roots, water use efficiency and yield in spring wheat under drip irrigation in the arid region of Xinjiang. The spring wheat cultivar ‘Xinchun 19’ was used as test material. There were four irrigation amount treatments in the fixed field trail, including no irrigation(W0), 1 500(W1),4 500 (W2) and 3 750 m/hm (Wck). The experiment measured the vertical distribution and dynamic change of root length density, root volume, root mass of wheat in 0-100 cm soil depth at jointing stage, heading stage, flowering period and mature period. The result showed that there was the lowest soil moisture content and highest water consumption of wheat root during flowering period. The largest amount of roots (i.e., root mass,root length density and root volume) was detected at 0-20 cm depth range which was also the most active region for wheat root system. Total amount of root system in the surface layer was increased in the appropriate soil moisture (at Wck treatment). But excessive water (at W2 treatment) inhibited the growth of root systems, reduced the root activity and the absorption amount of water, water use efficiency and yield for wheat. Although low irrigation amount (at W1 treatment) increased total amount of root at deep layer of soil and contributed to using deep soil moisture for wheat and enhancing water use efficiency under dry conditions, the wheat yield was lower. An acute shortage of water (at W0 treatment) caused hard water absorption, root number decreasing at surface layer of soil and resulted in yield loss. Therefore, it is better to use water applied at Wck treatment under the condition of abundant water resources, considering the balance of water saving and high yield.