交替隔沟灌条件下夏玉米棵间蒸发研究

Soil Evaporation of Summer Corn under Alternate-furrow Irrigation Condition

利用微型蒸发器观测了交替隔沟灌和常规沟灌条件下夏玉米的棵间蒸发量,分析了棵间蒸发、降雨量和参照腾发量的变化趋势以及不同土壤水分处理下隔沟灌和常规沟灌夏玉米棵间蒸发的日变化规律;探讨了相对蒸发强度与叶面积指数之间的关系,并拟合了棵间蒸发与叶面积指数之间的回归方程;最后指明了在充分供水条件下,相对蒸发强度与表层土壤含水量有极其敏感的关系。试验结果表明,交替隔沟灌条件下的棵间蒸发量小于相同水分处理的常规沟灌的棵间蒸发量,随着土壤水分下限值的增加,交替隔沟灌和常规沟灌间棵间蒸发量的差值越来越小;相对蒸发强度随着叶面积指数的增加而下降,随着表层土壤含水量的增加而增加。

Soil evaporation of summer corn under alternate-furrow irrigation and conventional furrow irrigation condition was measured by using micro-lysimeters . Moreover, the change tendency of soil evaporation, rainfall and reference crop evapotranspiration, daily variation of soil evaporation between alternate-furrow irrigation and conventional furrow irrigation under different soil moisture treat- ments were analyzed in this paper. In addition, the relationship among soil evaporation, leaf area index and surface soil moisture was discussed as well as the equation between soil evaporation and leaf area index was established. In the end, this paper put forward that there was a sensitive relationship between relative evaporation intensity and surface soil moisture under sufficient irrigation. The resuits indicated that soil evaporation of alternate-furrow irrigation was lower than that of conventional furrow irrigation at the same treatment, the difference in soil evaporation between alternate-furrow irrigation and conventional furrow irrigation would become smaller and smaller with the increase of the lower limit value of soil moisture. The relative evaporation intensity decreased with the increase of leaf area index, while increased with the increase of surfaee soil moisture.