烤煙煙田微氣候變化研究
Microclimate Variation in Flue-cured Tobacco Fields
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摘要: 為了探明烤煙煙田微氣候的變化規(guī)律，利用小氣候全自動觀測記錄儀,，研究了烤煙煙田離地150 cm高處的氣溫和空氣相對濕度,，5 cm、10 cm,、15 cm,、25 cm和35 cm土壤深度的溫度變化規(guī)律，以及20 cm深度的土壤濕度變化情況,。結(jié)果表明,，煙田最低氣溫出現(xiàn)在6點左右，最高氣溫出現(xiàn)在15點左右,，氣溫極值出現(xiàn)時間在各個煙草生育時期差異不大,，不同時期土溫極值出現(xiàn)時間比氣溫有所推遲。氣溫和土溫的日變化可用正弦曲線 進行描述,。由于受煙株蒸騰作用的影響,，煙株生長前期空氣相對濕度呈上升趨勢，生長中期最高達（80%～90%）,，后期略有下降,。一天中，空氣相對濕度最大值出現(xiàn)在6－7點,，最小值出現(xiàn)在14點左右,。土壤相對濕度在旺長期最大（35%左右）。隨著煙葉采烤的進行,，煙田土壤相對濕度開始下降,，20 cm深度的土壤濕度日變化不太明顯。Abstract: Aiming at the microclimate changes in tobacco fields, full automatic recorder of microclimate was used in 2000 – 2001 to study the temperature and relative humidity (RH) at the points of 150 cm above ground, soil temperature in depth of 5cm, 10 cm, 15 cm, 25 cm and 35 cm, and RH in soil depth of 20 cm. The results indicated that the minimum and maximum air temperature occurred at 6:00 and 15:00, respectively, which changed little with the increasing growth stages, whereas the extreme value of soil temperature occurred later than that of air temperature in different growth stages. The diurnal variations on air temperature and soil temperature could be simulated by sinusoid: . Because of transpiration of tobacco plants, the air RH ascended in early stage, with peak point in middle stage, and slight descending in later stage. The maximum and minimum air RH appeared at 6:00 - 7:00 and around 14:00, respectively. Soil relative humidity reached its peak (35%) in rapid growth stages, yet descended with the increasing harvest time, while no evident changes were found in the diurnal variations on soil relative humidity.
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