Effect of moistube-irrigation on crop yield and water use efficiency

In this study, summer corn and winter wheat were used to explore the effect of moistube-irrigation on crop growth and yield to support the generalization and application of moistube-irrigation technology. Comparative experiment was set up in a completely randomized design in order to determine yield, water use efficiency of summer corn and winter wheat and soil electrical con-ductivity. The treatments of the experiment included moistube-irrigation with different distances between moistubes (60 cm, 40 cm and 20 cm) and subsurface drip irrigation and no irrigation as the controls. The irrigation amount of moistube-irrigation was 1/4-4/5 that of subsurface drip irrigation. The results showed crop yield decreases under moistube-irrigation treatments due to lower irrigation amount. However, the decrease was not significant for winter wheat though it was significant for summer corn. Water use efficiencies of both crops were not significantly changed under moistube-irrigation treatments compared with the treatment of subsurface dir irrigation, while the irrigation water use efficiencies of crops were increased significantly. While crop yield increased with decreasing moistube interval, crop water use efficiency and irrigation water use efficiency decreased. For the Lou soil region which contains less water, the best moistube layout distance in the region was 60 cm according to the results of crops yields and water use efficiencies. This improved irrigation water use efficiency without significantly reducing yield. In addition, moistube distance had little effect on soil electrical conductivity. With increasing soil depth, there was no significant difference (P>0.05) in soil electrical conductivity in each growth period of two crops. Also it's variation trends in moistube-irrigation and subsurface drip irrigation were very similar. It suggested that the effect of moistube-irrigation and subsurface drip irrigation on soil electrical conductivity was consistent. Therefore, moistube-irrigation was much as applicable in summer maize and winter wheat cultivation as subsurface drip irrigation. The correlation between crop yield and soil electrical conductivity at the 10-20 cm soil layer and average soil electrical conductivity at the 10-80 cm soil layer was significant under moistube-irrigation. Hence, it was feasible to estimate crop yield by using soil electrical conductivity at the 10-20 cm soil layer and average soil electrical conductivity at the 10-80 cm soil layer. The above research provided the basis for the application of moistube-irrigation technology in summer corn and winter wheat cultivation.