膜下滴灌条件对棉花蒸散量影响的室内试验

Laboratory experiment on effects of different mulched drip irrigation conditions on cotton evapotranspiration

【目的】探讨不同膜下滴灌条件对棉花蒸散量的影响,为滴灌技术参数的设计和灌溉制度的制定提供参考。【方法】设置室内模拟试验,采用称质量法获得棉花蒸散量,分析滴头流量(0.3,0.8 L/h)、灌溉水质(含盐量0.40,2.47,3.50 g/L)和灌溉水量(321,386 mm)对棉花蒸散量的影响。【结果】淡水充分灌溉时,小滴头流量(0.3L/h)下的棉花总蒸散量高于大滴头流量(0.8 L/h)。在灌水量、滴头流量相同时,咸水(含盐量3.50 g/L)灌溉棉花的总蒸散量明显低于淡水(含盐量0.40 g/L)和微咸水(含盐量2.47 g/L)灌溉,而淡水和微咸水灌溉棉花的总蒸散量基本相同。在滴头流量相同时,充分供水时棉花的总蒸散量高于非充分供水。【结论】棉花的蒸散量随滴头流量的增大而减小,随灌水量的增大而增大,随灌溉水矿化度的增大而减小,适量的微咸水灌溉不会明显影响棉花的蒸散量。

【Objective】 The study was done to explore the effects of different mulched drip irrigation modes on cotton evapotranspiration,and to provide reference for design of technical parameters of drip irrigation and determination of irrigation schedule.【Method】 A laboratory simulation experiment was carried out to obtain the cotton evapotranspiration by weighing method,and then the effects of different emitter discharges（0.3,0.8 L/h）,irrigation water qualities（0.40,2.47,3.50 g/L）,and irrigation amounts（321,386 mm） on cotton evapotranspiration were analyzed.【Result】 The cotton evapotranspiration under small emitter discharge（0.3 L/h） is higher than that under large emitter discharge（0.8 L/h） when the cotton is irrigated with sufficient fresh water.For the same irrigation amount and emitter discharge,the cotton evapotranspiration is almost the same under fresh water（0.40 g/L） and brackish water irrigation（2.47 g/L）,which is obviously lower than the cotton evapotranspiration under saline water irrigation（3.50 g/L）.For the same emitter discharge,the cotton with sufficient water supply has higher evapotranspiration than that with deficient water supply.【Conclusion】 The cotton evapotranspiration decreases with the increase of emitter discharge or mineralization degree of irrigation water,increases with the increase of irrigation amount.The blackish water irrigation with proper amount can not influence the cotton evapotranspiration significantly.