Experiment On Subsurface Irrigator With Big Container For Trees And The Movement Of Water And Salinity In Soil On Subsurface Drip Irrigation

Summary: A kind of irrigator applying to arbors in city virescence belts was studied, which has a great capacity and has no effect on scenery because it was buried round the roots of trees. It also has a lot of characters such as the filtration of water resource is undemanding, the seepage of water completely depends on gravity, the working stress of transporting water is low and so on.. After trials, the dynamics of the shape of the wetted body and the quantity of the water irrigated were studies. The technique of increasing level wetted areas by increasing level infiltrated border was provided in order to adapt to the distribution of tree roots and improve the water use efficiency (when the soil is clay loam, the level wetted distance is two times the vertical wetted distance, so the level wetted border is increased obviously). After the infiltration stopped, the second water distribution has an obvious effect on radius,cubage and average soil moisture content of the wetted body (After the water was irrigated 390 minutes the cubage of the wetted body increased 66.7% and the average soil moisture content declined from 41.49% to 24.89% when the quantity of irrigated water is o.7l). In the course of the second water distribution, the vertical diffusing speed is faster than level diffusing speed. The study of soil water and salinity shows that : on subsurface drip irrigation, based on the six treatments which the depths the infilitration devices buried were at 7cm and 14cm, and the quantity of the irrigated water is 3l,4l and 5l, the soil salinity degraded obviously after the water was irrigated 24 hour, especially when the depth which the infiltration device was buried at 7cm and the quantity of irrigated water is 5l. At last, city virescence in arid, semi-arid and season arid areas according to the local economic condition is suggested. And it is also suggested that a corresponding irrigation mold must be established on the local condition and make the techniques of subsurface drip Irrigation reach the high level of the world.