为了研究不同尺寸和材料的微型蒸渗仪在南京地区的适用性,2016-2017年在大田玉米和冬小麦田中采用不同尺寸和材料的微型蒸渗仪的观测棵间土壤蒸发量,对不同作物和气象条件下的测定土壤蒸发量的差异性进行统计分析,并得到玉米和冬小麦土壤蒸发量的季节变化。结果表明,叶面积指数较小时,降雨或灌溉后的晴天微型蒸渗仪测定的玉米和冬小麦的会出现最大土壤蒸发量,分别为6.0和4.6 mm/d；不同材料的蒸渗仪对玉米的土壤蒸发量没有显著性影响,但不同的尺寸对蒸发量的影响达到了显著性水平,大尺寸微型蒸渗仪测定的土壤蒸发量高于小尺寸；微型蒸渗仪的不同尺寸对冬小麦蒸发量的影响不显著；建议采用直径125 mm的铁皮或者PVC外筒,直径118或114mm的铁皮内桶测定南京地区玉米和冬小麦的棵间土壤蒸发量。

Soil evaporation is a key trait in determining water consumption research of agriculture in sparse crops or in early period of the growing stages in maize and winter wheat. After measuring soil evaporation using the micro-lysimeter with different material and size in the maize and winter wheat field, we analyze the seasonal variation of soil evaporation and its variance among different micro-lysimeter material and sizes. Results showed that the seasonal maximum of soil evaporation is 6.0 and 4.6 mm/d for the maize and winter wheat, which occurs in sunny days after precipitation or irrigation when the leaf area index was small in the beginning or maturing periods. The measurements of soil evaporation using different material micro-lysimeter have no significant difference in maize field, while the large diameter micro-lysimeters measure the soil evaporation higher than the small ones. However, the different size of micro-lysimeter has no effect on the measurement of the soil evaporation in the winter wheat field. Finally, we suggest that using the micro-lysimeter with 125 mm diameter for the outer barrel in steel or plastic, 118-114 mm diameter for the inner barrel in steel in the survey of soil evaporation in Nanjing area.