Soil Evaporation Characteristics of Orchard Trees under Different Irrigation Modes

In order to reveal the evaporation characteristics and mechanism of water saving of water storage pit irrigation,the daily soil evaporation intensity of the surface in different distances from the tree and the pit wall in different depths of the pit were measured by micro-lysimeters respectively,the meteorological elements of the surface and the pit were also measured by nk3500 handheld weather instrument.The results showed that the surface soil evaporation increased firstly with time and decreased then under surface irrigation while it decreased with time and was obvious lower under water-storage pit irrigation compared to surface irrigation,whose difference was significant(p0.01).The average surface soil evaporation increased firstly with time and then tended to be stable under surface irrigation while the pit wall evaporation increased firstly with time,decreased then,and finally tended to be stable under water-storage pit irrigation,whose difference was not significant.The total evaporation under water-storage pit irrigation was much 33%lower than that under surface irrigation and the biggest difference was 6 432mm3.The top evaporation intensity under surface irrigation was nearby 2.3times of that under water-storage pit irrigation.Water storage pit irrigation is recommended in the orchard.