寒地黑土区调亏灌溉对水稻蒸散影响 及其节水效果

为了确定寒地黑土区调亏灌溉对水稻蒸散量的影响及节水效果，采用蒸渗器试验法和田间水量平衡分析，开展水稻本田期不同灌溉模式需水规律与降水利用研究。结果表明，试验区域相对于调亏灌溉管理的水稻蒸散需水要求，多年平均降水量仅在返青、分蘖期有所亏缺，灌溉水主要满足泡田期用水和深层渗漏导致的水量消耗。为此，调亏灌溉的净用水量可降低到390 mm，节水效果比浅晒浅灌节约灌水量51.9%，地下渗漏量是浅晒浅灌的37.43%，降水有效利用率较充分灌溉模式提高4.2%以上。

Impact of regulated deficit irrigation on evapotranspiration of rice in cold black-soil region and its water saving effect

The test with lysimeter and the analysis of field water balance are adopted to study the water demand law and precipitation utilization for various irrigation modes of the prime field period of rice,so as to determine the Impact of regulated deficit irrigation on evapotranspiration of rice.The results show that compared with the water demand of the deficit irrigation within the testing area,the average annual precipitation is only deficient to a certain extend during the green-up and tillering period and the irrigation water is mainly used to meet the water demand during the ponding period and the water consumption caused by the deep seepage.Therefore,the net duty of water of the regulated deficit irrigation can be lowered to 390 mm,and then 51.9% irrigation water is to be saved for the water saving effect and the underground seepage is to be decreased to 37.43%,if compared with the mode of shallow drying and shallow irrigation,moreover,the effective utilization rate of precipitation is to be increased by 4.2%,if compared with that of the mode of the sufficient irrigation as well.