不同供水条件下土壤水分与烤烟蒸腾耗水的关系

Relationship between soil moisture and transpirational water-consumption of flue cured tobacco under different water supplying conditions

采用旱棚人工控水试验,研究了不同供水条件下烤烟的生理需水规律及蒸腾耗水与土壤水分的关系。结果表明,在充分供水条件下,烤烟全生育期蒸腾耗水量的变化呈单峰曲线,以旺长期蒸腾耗水量最大,成熟期次之,伸根期最小,各时期蒸腾耗水模系数分别为45.23%,34.8%和19.97%。烤烟的蒸腾耗水量与土壤供水量成正比,各生育期供水不足均影响烟株的蒸腾耗水,尤其以旺长期干旱的影响最大。根据本试验结果,计算出了不同供水条件下烤烟蒸腾耗水的土壤水分胁迫系数,建立了非充分供水条件下土壤水分胁迫系数的订正函数和烤烟实际蒸腾耗水的时间-水分函数模型。

Through artificial water control experiment in the shed of rain-free condition, the physiological water requirement patterns of flue-cured tobacco and the relationships between transpiration water consumption and soil water content were studied under different water supplying conditions. The results showed that the change of evapotranspiration in the whole growing period of tobacco plant had a single-peak curve under abundant water supplying conditions. The maximum water consumption of transpiration was at vigorous growing stage, followed by maturing stage and relatively small at root extending stage, which accounted for 45.23%, 34.8% and 19.97% of total water consumption, respectively. The transpiration water consumption of flue-cured tobacco was increased with the increase of soil water supplying, and the effects of drought stress at different growing stages on tobacco evapotranspiration were significant, especially at vigorous growing stage. On the basis of this experiment, the correction coefficients of soil water stress for transpiration of flue-cured tobacco under different water supplying conditions were worked out. Furthermore, the correction functions of transpiration water consumption to soil water supplying and the time-soil moisture model of practical transpiration water consumption for flue-cured tobacco were also put forward under insufficient water supplying conditions.