晚稻全生育期气温、水温、泥温特征及避灾应用

Late Rice: Characteristics of Air, Water and Soil Temperature During Whole Growth Period and Their Applications to Mitigating Disasters

为研究双季晚稻全生育期气温、水温、泥温特征及寒露风避灾措施,应用农田小气候与实景观测系统等开展研究。试验表明:晚稻营养生长期以水温积温最高,生殖生长期以泥温积温最高。营养生长期日均气温、水温、泥温相差较大,孕穗后三者粘合并同步大幅下降。中午水温与日照时数呈正相关、与叶面积指数呈负相关。水温维持较高时长为14 h、高于早稻,是低温灾害的首选干预介质。寒露风来临时,气温下降迅猛并在6:00出现极值,日均气温较日均水温低2℃,最低气温可较水温极值低5.3℃。水温全天较稳定,灌深水保温可平缓早晚气温尖锐低谷,日平均气温比无措施提升1.5℃。遇大晴天实施排水晒田,在11:00后水温、泥温都呈明显上升。抽穗后期灌浆前期寒露风对秕谷率影响较大,采取灌深水+遇晴排水晒田的综合措施对秕谷率、空壳率、千粒重改善最明显。

The paper aims to analyze the characteristics of air, water and soil temperature during the wholegrowth period of late rice and the measures to avoid cold-dew wind disaster, environmental temperatures wererecorded using a cropland microclimatic and real observation system. The results indicated that： theaccumulated water temperature was the highest during the vegetative stage and the accumulated soiltemperature was the highest during the reproductive stage. The differences among daily mean air, water andsoil temperature were quite big during the vegetative stage. They were close and synchronously declined afterthe booting stage. The water temperature at noon was positively correlated with sunshine hours and negativelycorrelated with leaf area index（LAI）. Water temperature was higher for 14 hours, which was longer than that ofearly rice. Water could be used to adjust low temperature. When cold-dew wind occurred, air temperaturedropped rapidly and the minimum appeared at 6：00. The daily mean air temperature was 2℃ lower than dailymean water temperature, the minimum air temperature was 5.3℃ lower than the minimum water temperatures.All day long the water temperature was stable, deep-water irrigation could smooth the morning and nighttemperature drop, this might enhance the mean air temperature for 1.5℃. Drainage and drying field in sunnydays, water and soil temperature were upward significantly after 11：00. Cold-dew wind after the headingcaused the shriveled grain increase. After deep-water irrigation, drainage and drying field in sunny days couldreduce the rate of shriveled grain and the rate of unfilled grains, and improve thousand kernel weightsignificantly.