Effects of sprinkler irrigation on the field mieroclimate

The experiment of the effects of sprinkler irrigation on the field microclimate shows that sprinkler irrigation affects the air temperature 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 1ong time，the air temperature is decreased sharply，and the vapor pressure within heights from lm to 4m is significantly increased near canopy under sprinkler irrigation condition．Daily soil temperature amplitude under sprinkler irrigation condition is smaller than that under surface irigation condition at ground surface．The temperature amplitude decreases sharply as depth increa ses under both sprinkler irrigation and surfaca irrigation conditions．Total water uses during winter wheat growing period are 436．5mm and 459．4 mm under both sprinkler irigation and surface irrigation conditions，respectively．However，the winter wheat yield under sprinkler irrigation is 6430kg/hm²，and 4455kg／hm²under surface irrigation condition．The water use efficiency(WUE )of winter wheat on the field under sprinkler irrigation condition is 1．47kg／m³ while it is 0．97 kg／m³ under surface irigation condi．tion．WUE under sprinkler irrigation condition is about 52％ higher than that under surfaca irigation condition.