喷灌对冬小麦生长环境的调节及其对水分利用效率影响的研究

研究了在不同气候条件下喷灌对近地面空气温湿度和农田蒸发能力（冠层顶部20 cm蒸发皿水面蒸发量）的影响，在干热风天气条件下微量喷水对冠层温度和农田蒸发能力的影响，以及喷灌对冬小麦产量和水分利用效率的影响。试验结果表明，如果4～5月份降水量较少、空气相对湿度较低，则喷灌会明显降低近地面空气日最高温度和日平均温度，增加日平均相对湿度特别是最低相对湿度。喷灌条件下农田蒸发能力明显低于地面灌溉。微量喷水明显降低冠层温度和降低农田蒸发能力。农田蒸发能力变化与喷水量和日最高温度成正比，与日最低相对湿度和风速成反比。喷

Regulation of field environmental condition by sprinkler irrigation and its effect on water use efficiency of winter wheat

A field experiment was carried out to study the effects of sprinkler irrigation on air temperature and humidity near ground surface, field evaporation potential (water surface evaporation measured using 20 cm standard pan on the top of canopy) and water use efficiency of winter wheat under different climate conditions. A cooling treatment by spraying a little amount of water using sprinkler irrigation system was also conducted. Its effect on canopy temperature against the dry hot wind was studied. Experimental results show that sprinkler irrigation significantly decreased the maximum and average daily air temperature and increased the minimum and average daily relative humidity when it was dry. Field evaporation potential in sprinkler irrigation field was greatly lower than that in surface irrigation field. Cooling treatment showed that spraying little amount of water can greatly decrease canopy temperature. Decrease of field evaporation potential is positively related to spraying water quantity and the maximum daily temperature, and negatively related to the minimum relative humidity and wind speed. Winter wheat yield and water use efficiency under sprinkler irrigation condition were higher than that under surface irrigation condition.