Effects of sprinkler irrigation on the field microclimate

The experiment of the effects of sprinkler irrigation on the field microclimate shows that sprinkler irrigation affects the air temperat ure and humidity near crop canopy not only at the sprinkler day but also during the whole sprinkler irrigation season. The air temperature inversion appears for a very long time, the air temperature is decreased sharply, and the vapor press ure within heights from 1m to 4m is significantly increased near canopy under s pr i nkler irrigation condition. Daily soil temperature amplitude under sprinkler irr igation condition is smaller than that under surface irrigation condition at gro und surface. The temperature amplitude decreases sharply as depth increases unde r both sprinkler irrigation and surface irrigation conditions. Total water uses during winter wheat growing period are 436.5mm and 459.4 mm under both sprinkle r irrigation and surface irrigation conditions, respectively. However, the winter wheat yield under sprinkler irrigation is 6430kg/hm 2, and 4455kg/hm 2 under s urface irrigation condition. The water use efficiency (WUE) of winter wheat on the field under sprinkler irrigation condition is 1.47kg/m 3 while it is 0. 97 kg/m 3 under surface irrigation condition. WUE under sprinkler irrigatio n condition is about 52% higher than that under surface irrigation condition.