Water Supply Law of Negative Hydraulic Head Irrigation System

To sum-up the law of negative hydraulic head irrigation system,comparing of tomato experiment under negative hydraulic head irrigation and normal irrigation was carried out,soil water content distribution under different water supply tension was studied,the difference of plant sap flow and water consume under two irrigation methods was also analyzed.The results showed that negative hydraulic head irrigation system run stable,system can supply proper water for plant automatically,properly enhance the sap flow of tomato,and increase the yield potential of plant;soil water content can be change by adjust the water supply tension,the fluctuate of soil water content temporal distribution and spatial distribution under negative hydraulic head irrigation system are small,the irrigation represent uniformity;soil leakage can be reduced and negative hydraulic head irrigation system and repeated drying and wetting of soil profile cannot be avoided under negative hydraulic head irrigation system,water consume under negative hydraulic head irrigation system is less than normal irrigation,the effect of water saving is represented.