喷灌农田小气候变化及其对作物生长影响的研究进展

Review of the field microclimate change and it' effects on crop growth under sprinkler irrigation condition

喷灌对田间小气候和作物生长的研究综述与分析认为 :喷灌水滴蒸发和冠层截留蒸发是喷灌能够调节农田小气候的主要原因。喷灌水滴蒸发量一般小于 2 5 % ,冠层截留一般在 1%～ 4 2 %的范围内。喷灌农田冠层温度降低、湿度增大。在寒冷季节 ,通过喷灌可改善作物冠层的热量状况。喷灌后田间作物光合速率提高 ,蒸腾强度降低。最终表现为喷灌条件下作物耗水量较小 ,产量和水分利用效率较高。作物冠层的截留水量是喷灌能够长时间调节田间小气候的主要原因之一。进一步研究冠层截留水量在冠层内的分配、存储 ,冠层内的水汽交换、温湿度变化、冠层内水分的消散过程、喷灌后温湿度的空间分布等 。

The review of field microclimate change and it' effects on crop growth under sprinkler irrigation condition was concluded that evaporations of sprinkler droplets and canopy interception water under sprinkler irrigation condition are major factors that affect the field microclimate. The direct evaporation of sprinkler droplets is experimentally less than 25% of total water irrigated, and the canopy interception water is usually within the range of 1%～42% under field experiment condition. The air temperature near canopy is lower and humidity is higher under sprinkler irrigation condition. During cold days, sprinkler irrigation can improve the heat situation of plant canopy. Crop photosynthesis rate is increased and the transpiration rate will be decreased under sprinkler irrigation condition. And then the evapotranspiration is low, and the yield and water use efficiency are high. Crop canopy interception water is one of the key factors that affect the field microclimate during a long period under sprinkler irrigation condition. To further study the water distribution and storage of canopy interception water, vapor exchange, air temperature and humidity changes, the process of water dispersion within the crop canopy, the temporal and spatial distribution of air temperature and humidity during and after sprinkler irrigation will be very useful to clearly analyze the crop evapotranspiration and crop water use efficiency under sprinkler irrigation.