Investigation on soil water redistribution under drip irrigation condition

The test was carried out on air-dried sandy soil to investigate the course of soil water redistribution under drip irrigation condition.It was discovered that the water content at the spot that was close to the dripping points dropped by 1%～2% suddenly after the course of water redistribution began.Afterwards,the soil water content of this spot reduced along with the time,and it reduced quickly in the earlier period,but slowly in the later period.The water content of the original wetting front edge continued to increase in the earlier period of soil water redistribution,but reduced slowly along with the time in the later period.The movement of soil water redistribution enabled the soil water content in the wetting region to drop to some extent,and the soil water was shifted from high moisture section to low moisture section.Under the experiment condition,the horizontal wetting distance grew up by 6%,and the vertical wetting distance grew up by 9%.The movement of soil water achieved the temporary balance in 24 h after stopping irrigation.Subsequently the change of the soil water content became very small,and the wetting front was kept nearly un-expanded.