不同类型微型蒸发器测定土壤蒸发的田间试验研究

利用微型蒸发器(Micro-Lysimeter，简称ML)测定土壤蒸发是一种简单、有效的方法，在中国西北旱区有很大的利用价值，但目前还没有统一的ML设计标准，所以寻求适合西北旱区使用的ML类型具有重要的现实意义。该文利用不同直径、不同长度、不同材料以及不同封底情况的ML在西北旱区进行了砂土和壤土的蒸发测量试验。研究结果表明：测得的土壤蒸发量随ML直径的增大而减小，不同直径ML测得的蒸发量在0.05的水平下有显著差异，测量砂土蒸发采用直径为15 cm的ML效果较好，壤土采用10 cm的较为理想。直径较小的情况下，ML的长度对蒸发量的影响显著，直径较大时则不显著，ML的长度以20c m为宜。ML的制作材料和是否封底对蒸发测量也有显著影响，在西北旱区，采用PVC不封底的ML较好。

Field experimental study on the measurement of soil evaporation using different types of micro-lysimeters

Measurement of soil evaporation using micro-lysimeter(ML) is a simple and effective method, and has great practical value in arid area of Northwest China. However, there is no uniform standard for ML design up to now. So, there is practically significance to seek ML which is applicable in such area. In this paper, some experiments for measuring evaporation using micro-lysimeters had been conducted in sandy soil and loam by MLs including different diameters, lengths, materials, sealed and unsealed. Results show that the longer the diameter of ML is, the less evaporation measured is. The difference is significant at 0.05 probability level among the evaporation values measured by ML with different diameters. The evaporation value measured with ML of 15 cm diameter is most appropriate for sandy soil, while 10 cm diameter ML is better for loam. When the diameter is shorter, the effect of length of ML on evaporation is significant, but it is not significant when the diameter is longer. ML of 20 cm length is most appropriate. The influences of the material and sealed type of ML on evaporation value are also obvious. In detail, the unsealed ML made with PVC is better for evaporation measuring in arid area of Northwest China.